Open Source App Cloud Marketplace

From a freelancer logging billable hours to companies with hundreds of users, Kimai scales professional-grade open-source time tracking - a Symfony/PHP application without the per-seat pricing of Harvest or Toggl. Tracking is flexible by design: run multiple concurrent timers, use punch-in/punch-out mode, or enter times manually, organized by customer, project, and activity with tags, and priced by user-, customer-, or project-specific rates. The billing pipeline is where Kimai earns "professional grade": generate invoices directly from timesheet data with configurable templates (DOCX, ODS, XLSX, PDF), entry grouping, and invoice-number generators, while an export flag locks billed records against editing and excludes them from future invoices - the audit-safety detail spreadsheet workflows never get right. E-invoicing supports EN 16931, XRechnung 3.0, and Zugferd/Factur-X. Enterprise controls come standard: SAML and LDAP login against Google Workspace, Azure AD, or Authentik, TOTP two-factor auth, customizable role permissions, and teams that scope customers and projects to departments. Money and time budgets alert before overruns, advanced reporting slices recorded time by any dimension, and an extensive JSON API plus a plugin marketplace (expenses, approvals, and more) integrate it with existing infrastructure. Over 30 translations, multi-timezone, AGPL-licensed.

Roughly 43% of all websites and over 60% of the CMS market run on WordPress - the GPL-licensed platform that scales from a personal blog to publishing operations and WooCommerce stores. The Gutenberg block editor composes pages from reusable blocks, and full site editing extends block control to headers, footers, and templates; tens of thousands of plugins and themes cover essentially every capability a site might need, from SEO and caching to membership and e-commerce. WordPress 7.0 "Armstrong" marks the platform's biggest structural update since Gutenberg itself: a React-based DataViews admin replaces the legacy list tables with instant filtering, a provider-agnostic AI Client API ships with connectors for OpenAI, Anthropic, and Google, media processing moves into the browser via WebAssembly, and a universal Font Library manages typography across block, hybrid, and classic themes with local hosting for GDPR compliance. New Breadcrumbs, Icons, and lightbox Gallery blocks reduce plugin dependence, and server-side PHP block registration simplifies development. The REST API and WP-CLI make it automatable end to end. Self-hosting is what WordPress was designed for: your content, database, plugin choices, and upgrade schedule stay entirely under your control, free of wordpress.com plan limits.

Most design tools stop at prototyping; Quant-UX also measures how real users actually perform with the prototype. The visual editor creates prototypes that behave like real apps - functional input widgets, animations, form validation, data binding across screens, and business logic modeled with REST requests and decision elements. Design systems are first-class, with components, design tokens, and master screens; if you design elsewhere, drop in image files or import from Figma. Testing is a shared link or QR code - no installs on the tester's side. Define user tasks up front, and Quant-UX records every session: click heatmaps show where users found (or missed) actionable elements, user journey graphs expose lost users, drop-off charts reveal where tasks stall, and success rates and task KPIs are extracted automatically into a dashboard. An A/B test operator wires two design variants into one prototype and compares task duration, success rate, and interaction counts. In-prototype surveys collect qualitative feedback alongside the numbers, and an AI assistant generates prototype fragments like styled forms on request. The RepoCloud deployment runs the full stack - frontend, backend, and WebSocket server containers over MongoDB - so all test recordings and research data stay on your infrastructure.

Stocks, ETFs, crypto, bonds, precious metals, and cash across every account and currency, in one privacy-first dashboard: Ghostfolio is open-source wealth management software. The deliberate design decision is no brokerage linking: positions enter by manual entry, CSV import, or the REST API, so your holdings never pass through a data aggregator. Performance is measured as return on average investment across Today, WTD, MTD, YTD, 1Y, 5Y, and Max timeframes, with benchmark comparison against indices like the S&P 500, dividend tracking, and allocation breakdowns by asset class, region, and sector. A static X-ray analysis flags concentration and other portfolio risks, and a FIRE calculator projects progress toward financial independence. Multi-currency support converts holdings using historical exchange rates, market data comes from Yahoo Finance and CoinGecko among other pluggable providers, and everything exports back out as CSV or JSON. Built with Angular and NestJS on PostgreSQL and Redis, shipped as Docker images for amd64 and ARM, with a mobile-first PWA interface, dark mode, and a distraction-free Zen mode. AGPL-licensed.

Spotify economics without the subscription or catalog gaps: Navidrome, the reference self-hosted music server, streams your own FLAC, MP3, and ALAC collection from a single Go binary with a React/Material UI web player. Its Subsonic/OpenSubsonic API compatibility is the superpower: 50+ existing clients work out of the box, from Symfonium and DSub on Android to Feishin and Sonixd on desktop, plus Android Auto, CarPlay, and Android TV apps. Transcoding is server-managed and FFmpeg-backed - FLAC direct-plays at home and downsamples to MP3, AAC, or Opus over mobile bandwidth, with the OpenSubsonic transcoding extension letting clients declare capabilities and receive per-track direct-play or transcode decisions automatically. Multi-user support gives every account its own play counts, favorites, ratings, and playlists, and multi-library support scopes different collections to different users. The feature list covers serious listening: Last.fm and ListenBrainz scrobbling, artist bios and images, embedded and external lyrics, audiobook bookmarks, saved play queues that resume on another device, internet radio, jukebox mode, and M3U playlist auto-import kept in sync with your folder. Resource usage is famously low - it runs happily on a Raspberry Pi and scales to six-figure track counts.

Machine translation with no Google, no Azure, no per-character billing, and no text leaving your infrastructure: LibreTranslate is a free, open-source translation API that runs entirely on your own server. The engine underneath is Argos Translate, which runs OpenNMT neural models with SentencePiece tokenization and Stanza sentence-boundary detection, all offline. Models install as portable .argosmodel packages covering dozens of languages - English, Spanish, French, German, Chinese, Japanese, Russian, Arabic, Hindi, Portuguese, and many more - and Argos handles automatic pivoting: with es-to-en and en-to-fr installed, it chains them to translate es-to-fr without a direct model. The API is a straightforward HTTP POST to /translate with source and target language codes, returning JSON - simple enough that the ecosystem has clients in every major language and integrations across tools like Weblate and Mastodon. Beyond plain text it translates HTML while preserving markup and handles whole file uploads (documents in, translated documents out), plus automatic language detection when the source is unknown. A clean bundled web UI serves interactive translation for end users, and optional API keys with rate limits control access. AGPL-licensed and trainable with custom models, it is the standard answer when translation must be private, unmetered, and self-contained - GDPR-sensitive text never touches a third party.

Memos, the lightweight open-source note service from the usememos project, packaged as a containerized deployment for multi-architecture Docker hosts (x86-64 and arm64): that is Usermemos. The model is frictionless capture: no folders or titles, just a chronological stream of Markdown notes with code blocks, task lists, tables, and file attachments, organized by #hashtags pulled automatically from the text. Per-memo visibility - private, protected for logged-in users, or public - lets a single instance serve as a personal journal, a shared team log, or a public microblog simultaneously. Multi-user support with authentication makes it workable for small teams, and full REST and gRPC APIs open capture and retrieval to CLIs, bots, and automation tools. The runtime is a single Go binary with a React frontend that idles around 50 MB of memory and stores content as plain Markdown in SQLite by default, with MySQL and PostgreSQL available for heavier deployments. Configuration happens through environment variables, access works over HTTP or HTTPS behind a reverse proxy, and there is no telemetry - notes stay on your server in a portable format.

Wrap code in a flag, then toggle it per environment, per user, per segment, or by percentage - no redeploy required: Flagsmith is an open-source feature flag and remote config platform. Every flag doubles as remote config, carrying string, number, or JSON values, so functional and visual changes ship to production without a code push. Segments are the targeting engine: build them from stored user traits, then release to beta testers first, test in production by exposing features only to internal teams, or run canary deployments to a small percentage before going wide - segment membership changes instantly without app updates. Multivariate flags split traffic across two or more variations for A/B/n testing, with flag events flowing into Amplitude, Mixpanel, or Segment for analysis. SDKs cover 15+ languages including TypeScript, .NET, Java, Python, and Go, with framework support for React, Next.js, and mobile, plus local evaluation for latency-sensitive paths. Organizations, projects, and roles keep multi-team setups tidy. Core functionality - unlimited flags, remote config, targeting, multivariate flags - is BSD-3-Clause licensed with an explicit commitment that it stays open. Self-hosting suits privacy-conscious teams: flag rules and user traits stay on your infrastructure, deployable via Docker or Kubernetes with Helm.

Serious readers organize, convert, edit, and serve their e-book libraries with Calibre - the definitive open-source e-book manager. This deployment runs the full Calibre desktop application on your server, accessible from any browser, so your library lives in one authoritative place instead of scattered across devices. Its conversion engine is the best in the business, translating between every major format - EPUB, MOBI, AZW3, PDF, DOCX, and dozens more - with fine control over fonts, margins, metadata, and structure detection. Metadata management downloads covers, descriptions, series info, and identifiers from online sources, and every field is editable in bulk. Beyond cataloging, Calibre includes a full e-book editor for EPUB and AZW3 internals, a news engine that fetches newspapers and magazines from the web on schedule and converts them into e-books, book comparison tools, and device syncing that sends the right format to each connected reader. The built-in content server exposes your library over HTTP so phones, tablets, and e-readers can browse and download remotely. A deep plugin ecosystem extends everything - metadata sources, format support, store integrations. For power users, the complete CLI (calibredb, ebook-convert) enables scripted library automation. Your books, your metadata, your server - permanent and DRM-free storage under your control.

ShareX and file uploads, next generation: Zipline is a Node.js/React/PostgreSQL server that turns screenshot sharing and file hosting into something you run yourself instead of renting from Imgur or a paid image host. The core workflow is built around ShareX: generate an .sxcu config from your account settings, import it, and every screenshot or clipboard capture uploads to your domain with a short link copied automatically. Uploads accept any file type, organized with folders and tags, with token-protected uploading, optional password protection, view-limited auto-deletion, image compression, metadata stripping, automatic video thumbnails, and chunked/partial uploads for large files. File URLs come in configurable formats - UUIDs, dates, random alphanumerics, original names, even zero-width spaces. A built-in URL shortener adds vanity slugs, passwords, view caps, and custom domains. Discord embeds are first-class: customize OG metadata titles, descriptions, and colors so links unfurl exactly how you want, and fire fully customizable Discord or HTTP webhooks on each upload. Authentication is serious: OAuth2 (Discord, GitHub, Google, OIDC), TOTP two-factor, and passkeys, with invite-based registration and per-user quotas for shared instances. Storage targets local disk or any S3-compatible backend, a full REST API automates everything, and custom themes plus a PWA round out the experience.

Half the architecture sketches on the internet trace back to Excalidraw - the MIT-licensed virtual whiteboard whose hand-drawn aesthetic made technical diagramming feel approachable, at roughly 85,000 GitHub stars. The infinite canvas offers rectangles, ellipses, diamonds, arrows with smart binding and labels, free-draw, text, images, and an eraser, with full undo/redo, zoom, dark mode, and keyboard-first ergonomics. Community shape libraries add thousands of pre-built elements - AWS architecture icons, flowchart stencils, UI wireframe kits - and everything exports to PNG, SVG, the clipboard, or the open .excalidraw JSON format that keeps drawings diffable and portable. Live collaboration works on a share-a-link model with live cursors and a laser pointer for presenting, and it is end-to-end encrypted by design: the room key travels in the URL hash, which never reaches the server, so the WebSocket relay only ever sees ciphertext. The architecture is remarkably light - the app is a static bundle served by Nginx, drawings persist locally in the browser, and the stateless excalidraw-room relay handles multiplayer - so a self-hosted deployment gives unlimited boards and collaborators with near-zero resource cost, replacing per-editor whiteboard subscriptions.

A recipe manager that feels like a consumer product rather than a homelab experiment: Mealie pairs a FastAPI backend with a reactive Vue frontend for the most polished self-hosted meal planning around. The killer feature is the recipe scraper: paste a URL from hundreds of supported cooking sites and Mealie imports the ingredients, steps, times, and photos automatically. Structured HTML/JSON paste, a Markdown-capable manual editor, and imports from other recipe apps (like Tandoor) cover everything else. Meal planning uses a drag-and-drop calendar with breakfast, lunch, dinner, and snack slots, plus rule-based random recipe insertion - constrain the pool by tags or categories per meal type or weekday. Shopping lists link recipes so all ingredients land in one place, organized into supermarket sections, and update in real time for everyone in the household. The multi-tenancy model is genuinely thought through: isolated Groups can host multiple tenants, and Households within a group share recipes and organizers while keeping meal plans and shopping lists private. Cookbooks group recipes by your own criteria, a cooking mode stays readable on a phone propped against the backsplash, and 35+ language translations ship built-in. A fully documented REST API and scheduled webhooks (e.g., today's meal plan to Home Assistant) make it automatable, with SQLite or PostgreSQL storage and automatic backups.

Google Workspace and Microsoft 365, replaced by a platform you actually control: Nextcloud is the self-hosted digital workspace. Files is the core: file storage and sync across desktop, mobile, and web clients, with sharing, versioning, and collaboration built in. Around it, Talk provides private text chat, audio/video conferencing with screen sharing, SIP integration, and persistent voice rooms; Groupware bundles calendar, contacts, and mail with delegation support; and Office offers two collaborative suites - the Collabora-based option with deep ODF support, and Euro-Office, whose local-processing architecture delivers strong Microsoft Office compatibility and fast browser rendering with reduced server load. The Nextcloud Assistant threads AI through the platform via a context-aware sidebar, Whiteboard covers visual collaboration, Flow handles automation, and an app ecosystem of hundreds of extensions adds everything from Kanban boards to end-to-end encryption. Hub 26 brings a lighter UI with a unified app switcher and Nextcloud Governance for organizations under strict regulatory requirements. This is the flagship of data sovereignty: your files, chats, calendars, and documents live on your server, under your jurisdiction, with GDPR compliance by architecture rather than by contract.

Price drops, restocks, job postings, government announcements, competitor edits - changedetection.io watches web pages and alerts you the moment anything changes, down to PDF text and checksums. Point it at a URL, set a check interval, and precise filters decide what counts as a change: a Visual Selector targets page elements by pointing and clicking, CSS selectors and XPath narrow scope, trigger-text and ignore-text rules (with regex support) cut noise, and JSONPath or jq handles API responses. A dedicated re-stock and price detection mode extracts product metadata and fires on thresholds - alert only when the price drops below your target or the percentage change exceeds a limit. JavaScript-heavy sites render through a real Chrome browser via Playwright, with the ability to execute JS steps first (log in, click, scroll) before extracting text. Notifications reach 85+ services through Apprise - Discord, Slack, Telegram, email, webhooks - optionally with a screenshot of the changed page, and AI-powered summaries (any OpenAI-compatible endpoint, including local Ollama) describe what changed. Per-watch proxies, custom headers, and POST/GET control cover hostile targets. Apache-2.0 licensed with local file-based storage: the URLs you monitor and why stay entirely your business.

Real-time alerts from your own infrastructure to your phone, with no Firebase, Pushover, or third-party push service in the path: Gotify is a simple, self-hosted notification server written in Go. The model is deliberately minimal: senders push messages with a single HTTP POST to the REST API, receivers subscribe over a WebSocket stream, and a clean React web UI manages the pieces. Senders are namespaced as "applications," each with its own token, so your backup script, Uptime Kuma, CI pipeline, and cron jobs each get an identity, an icon, and independently revocable credentials - centralized alerting from many services with per-source management. Messages carry a title, body, and priority level that maps to notification importance on the client. The official Android app (on both F-Droid and Google Play, notable for working entirely without Google Play Services) shows push notifications for new messages; the web UI itself supports Web Push in the browser; and gotify/cli pushes messages from shell scripts with one command. A server-side plugin system adds custom behavior, and the whole thing runs as a single small binary with SQLite by default - near-zero resource footprint. Because dozens of tools (and Apprise) speak Gotify natively, it slots in as the notification hub for an entire homelab or ops stack.

Up to 280 search services - Google, Bing, DuckDuckGo, Brave, Qwant, Startpage - aggregated without tracking or profiling: SearXNG is a privacy-respecting metasearch engine (AGPL-3.0, successor to Searx). Your instance queries the upstream engines on your behalf: your IP address, cookies, and search history never reach them, tracker parameters are stripped from result URLs, and an optional image proxy fetches thumbnails server-side so result pages leak nothing. It can even route outbound queries through Tor for full anonymity. Search is organized into categories - general, images, videos, news, maps, music, IT, science, files - with bang shortcuts for targeting specific engines, and every source can be enabled, disabled, or weighted per category in settings.yml. A plugin system adds calculators, hash tools, tracker removal, and unit conversions inline, and preferences (themes, safe search, languages, engine selection) persist in cookies rather than server-side accounts. The real argument for running your own instance rather than trusting a public one is control: you decide the logging policy (none), the engine mix, rate limiting, and who gets access - making it the default search backend for browsers, families, and teams that want Google-quality results without the profile.

Securing a SaaS product, running B2B onboarding, or replacing Auth0 and Keycloak with a stack they own - teams needing more than basic auth reach for ZITADEL, an open-source identity and access management platform built in Go. Its multi-tenancy model is the differentiator: a strict Instance, Organization, Project hierarchy isolates data and scopes policy at each level, with identity brokering (pre-built templates for Google, GitHub, Microsoft, Apple, plus generic OIDC, OAuth, SAML, and LDAP), domain discovery that routes users to the right organization by email domain, and delegated management so customers administer their own users and roles. Authentication covers OpenID Connect (certified, including device authorization and token exchange), SAML 2.0 as both IdP and SP, SCIM, FIDO2 passkeys for phishing-resistant passwordless login, and MFA via OTP, email, SMS, and U2F; machine-to-machine flows support JWT profile, PATs, and client credentials. The architecture is event-sourced - every mutation is an immutable event, yielding a complete audit trail - with relational projections for queries and no external session store, so it scales horizontally. API-first with gRPC and REST, extensible via Actions webhooks, and the same codebase self-hosted (Docker Compose or Helm on PostgreSQL) as in the cloud.

The ad-riddled "free online tools" sites people paste sensitive text into and upload confidential PDFs to - OmniTools replaces that whole ecosystem with one self-hosted app. It bundles 50+ utilities behind one clean React/TypeScript interface: image tools (resize, convert, crop, edit), video and audio tools (trim, reverse, convert), PDF tools (split, merge, edit), text and list utilities (case converters, formatters, shufflers), plus date/time, math, and data-format helpers for JSON, CSV, and XML. The architectural decision that makes it trustworthy is that all file processing happens entirely client-side in the browser - the server only serves static assets, and nothing you process ever leaves your device. That design has a pleasant side effect: the host needs almost no resources (people run it on a Raspberry Pi Zero), because your browser does the work while the server just delivers files. The Docker image is a remarkable 28 MB, making it one of the fastest apps to deploy and cheapest to keep running. There are no ads, no tracking, no accounts, and no upload limits. With multi-language support and an MIT license, it works equally well as a personal toolbox or a team-wide internal utility portal - one URL that replaces a bookmark folder full of questionable converters. Actively developed with 50 contributors and 9,500+ GitHub stars.