If you’ve ever looked up at the night sky and wondered “What star is that?”, Stellarium answers it beautifully.

🪐 Realistic sky rendering
🔭 Telescope control support
🌙 Perfect for the curious, casual stargazers and serious astronomy nerds
💻 Runs on desktop, mobile, and even in the browser

It’s clean, powerful, and completely free

Flying Carpet is an open‑source project that makes file transfer across devices simple and secure. Think of it as a cross‑platform alternative to AirDrop: no central server, no complicated setup, just two devices in close range using WiFi (and optionally Bluetooth). It’s designed to work seamlessly across Android, iOS, Linux, macOS, and Windows.

Key Features

📱 Cross‑platform support – Works on Android, iOS, Linux, macOS, and Windows.

📡 Ad hoc WiFi transfers – No network infrastructure required; devices connect directly.

🔒 Optional Bluetooth negotiation – Adds flexibility for initiating transfers.

⚡ Fast & lightweight – Simple interface, efficient transfer speeds.

🛠️ Open source – Built in Rust and Kotlin, available on GitHub for contributions.

🎥 Demo video & installers – Easy to get started with prebuilt binaries and clear documentation.

Quick links to app stores are on the github page. For Windows, Linux and MacOS look under "Releases" under the "About" section.

Wealthfolio is a beautiful, open-source portfolio tracker that runs locally on your devices. It helps you monitor all your accounts in one place, analyze performance, track dividends and fees, and set financial goals — all while keeping your data private and under your control.

⭐ Features

🔒 Privacy-first — Runs locally, keeping your financial data secure and offline.

📂 Account aggregation — Import CSV statements and view all accounts together.

📊 Analytics — Track asset allocation, fees, dividends, and interest earnings.

📈 Performance insights — Compare accounts against indexes and ETFs, view past trends.

🎯 Goal tracking — Define financial goals and monitor progress visually.

📅 Trading tracker — Simple swing stock trading with calendar views and performance analytics.

🛠️ Open-source — Transparent, community-driven development.

End-to-End Encrypted Location Sharing without big corp collecting, storing and profiting your data.

Description:

🔑 End-to-End Encryption (E2EE): Your GPS data is encrypted before leaving your phone. Not even Grid can see it.

🗺️ Private Maps: Uses open-source Protomaps instead of Google/Apple, eliminating third-party tracking.

⚙️ Full Control: Expiring shares, instant revocation, unlimited groups — your rules, no paywalls.

🛡️ Zero Data Exploitation: No ads, no trackers, no data sales.

🌍 Open Source: Built on the Matrix protocol, independently audited by NCC Group, Least Authority, and German BSI.

📱 Cross-Platform: Available on iOS & Android, with self-hosting options for maximum control.

👥 Use Cases: Family check-ins, hiking, cycling, moto clubs, travel coordination, and field work teams.

Why it matters:

Grid stands out in the location-sharing space by prioritizing privacy, transparency, and user empowerment. Unlike mainstream apps that monetize your movements, Grid ensures your data stays yours. Perfect for anyone who values security while staying connected.

Habitica is a free habit‑building and productivity app that turns your real life into a role‑playing game. By completing tasks, you earn rewards, level up your avatar, and collaborate with friends to stay motivated.

✅ Track habits, daily goals, and to‑do lists with ease

🎁 Earn rewards, unlock pets, skills, and quests as you progress

⚔️ Battle monsters with friends and join parties for accountability

🖥️ Cross‑platform support with web and mobile apps (iOS, Android)

🔧 Fully customizable task lists to fit personal goals and projects

💪 Improve health, fitness, school, and work productivity through gamification

🤝 Open‑source project supported by a strong community

Perfect for: Anyone who wants to stay motivated by turning productivity into a fun, game‑like experience.

AirGuard is an open-source Android app that protects against unwanted tracking via Apple AirTags and other Find My devices. Key features:

🔎 Periodic Bluetooth scans to detect nearby AirTags & trackers

📍 Alerts if a device follows you across multiple locations

🔔 Play sound on detected AirTags to locate them quickly

🗺️ View maps of where tracking devices were detected

🔒 All detection and location data stays local on your device

🧪 Option to contribute anonymized data to research (privacy-respecting)

🚫 No ads, no monetization — purely privacy-focused

Ideal for anyone concerned about covert tracking and wanting a transparent, community-driven defense tool.

Signal is a free, open-source messenger built around privacy-first principles. Every message and call is protected with state-of-the-art end-to-end encryption powered by the Signal Protocol.

Unlike mainstream apps, Signal has no ads, no trackers, and no corporate ownership—it’s run by an independent nonprofit sustained by donations.

Key highlights:

🔒 Secure by default: Encryption for every message, every call, every time.

💬 Rich communication: Text, voice, video, GIFs, files, and even encrypted stickers.

👥 Group chats: Stay connected with family, friends, and coworkers without surveillance.

🌍 Cross-platform: Available on Android, iOS, Windows, Mac, and Linux.

🕊️ Nonprofit model: Independent, community-supported, and never for sale

Destiny is an open-source secure file transfer application built on the Magic Wormhole protocol. It allows users to send files in real time without revealing identities or storing data on servers. Key features:

🔒 End‑to‑end encryption for safe delivery

🌐 Peer‑to‑peer connections with no central storage

🧩 Short, human‑memorable codes for quick and secure transfers

🛡️ Designed with human rights organizations in mind

✅ Independently audited for security assurance

💻 Cross‑platform support: Android, iOS, Windows, macOS, Linux

Perfect for anyone who needs fast, private, and trustworthy file sharing without compromising on security.

ActivityWatch is a free, open-source app that automatically tracks how you spend time on your devices. It’s privacy-first, cross-platform, and a great alternative to RescueTime, ManicTime, or WakaTime. Key features:

📊 Tracks app usage, websites, and overall activity automatically

🔒 Privacy-focused: all data stored locally, no external servers

💻 Cross-platform support: Windows, macOS, Linux, Android

⚙️ Highly extensible with modules and custom watchers

📈 Insightful stats and visualizations to improve productivity or spot bad screen habits

🌍 Community-driven, transparent, and free forever

Perfect for anyone who wants clear insights into their digital habits without sacrificing privacy.

Rethink DNS + Firewall is a free, open-source Android app that makes it easy to monitor app activity, block ads and trackers, and circumvent Internet censorship. Key features:

🛡️ Android firewall: prevent apps from connecting to the Internet over Wi-Fi or mobile data

🚫 Content blocking: ads, trackers, malware, and more

🌍 Anti-censorship: encrypts DNS requests to bypass restrictions, with presence in 200+ locations worldwide

📊 Monitoring: logs every app’s connections and data usage

⚙️ Automated reports flag suspicious connections and reveal surveillance attempts

🔒 Privacy-first design, no accounts required

Perfect for anyone who wants system-wide privacy and control over their Android device.

SimpleX Chat is a free, open-source messenger designed for maximum privacy. Unlike other messaging networks, SimpleX has no identifiers assigned to users — not even random ones. Key features:

🔒 End-to-end encryption with no usernames, phone numbers, or public keys

📱 Private connections via link or QR code for messaging and calls

🌐 Pairwise anonymous addresses hide communication metadata from servers and observers

🛡️ Option to connect via Tor for extra anonymity

💻 Cross-platform support: Android, iOS, and desktop

🌍 Community-driven, open-source transparency

Perfect for anyone who wants truly private communication without digital footprints.

WiFi Analyzer (open-source) helps you examine surrounding WiFi networks and optimize your own connection. Designed with privacy in mind, it uses as few permissions as possible and requires no internet access. Key features:

📶 Measure signal strength of nearby WiFi networks

📊 Identify crowded channels to improve performance

🔒 Privacy-focused: no data collection, no hidden tracking

⚙️ Lightweight and open-source, fully transparent

📱 Android support with a clean, intuitive interface

Perfect for anyone who wants to boost WiFi performance and reliability while keeping privacy intact.

Loop Habit Tracker is a free, open-source Android app that helps you create and maintain good habits over time. It’s lightweight, privacy-respecting, and completely ad-free. Key features:

📈 Detailed charts and statistics to visualize progress

🔔 Flexible reminders to keep you on track

🔒 Privacy-first: no accounts, no tracking, all data stored locally

⚙️ Customizable habit frequency (daily, weekly, custom intervals)

🌍 Open-source transparency with active community contributions

📱 Clean, intuitive design optimized for long-term habit building

Perfect for anyone who wants to achieve long-term goals through consistent habit tracking without sacrificing privacy.

KeePassDX is an open‑source password manager for Android that keeps your digital identities safe in one encrypted file.

🔐 Store and manage passwords securely

✏️ Edit encrypted keys and identities

📝 Autofill forms with strong credentials

🔄 Compatible with other KeePass products

📱 High security + interoperability across devices

Perfect for: Android users who want a reliable, open‑source solution for managing passwords without compromising privacy.

LocalSend is a free, open‑source, cross‑platform tool that lets you share files instantly with nearby devices — no internet required.

📡 Send files directly over local network

🔒 Secure, private, and open‑source

💻 Works across Windows, macOS, Linux, Android, and iOS

⚡ Fast transfers without cloud dependency

Perfect for: Users who want a simple, private, and cross‑platform way to share files without third‑party servers.

Calibre is a powerful and easy‑to‑use e‑book manager that goes beyond normal e‑book software. It’s completely free and open source, making it a must‑have for both casual readers and power users.

⏱️ Save time on managing your e‑book collection

🌍 Use it everywhere and with anything

📖 Comprehensive e‑book viewer

📰 Download news and magazines from the web

📤 Share and back up your library easily

✏️ Edit the books in your collection

🛠️ Satisfy every e‑book need with community support

Perfect for: Readers and professionals who want a versatile, free, and open‑source solution for managing their digital libraries.

Jami is a free/libre, end‑to‑end encrypted, and private communication software. It offers peer‑to‑peer connectivity without central servers, ensuring privacy and freedom for its users.

⚡ Fast latency with direct peer‑to‑peer connections

🌐 Works even without internet on local networks

🛡️ End‑to‑end encrypted communications

🙅 No personal information required to create an account

📞 Unlimited: no restrictions on file size, bandwidth, or features

🚫 Ad‑free: there will never be advertising on Jami

Perfect for: Users who want secure, private, and unrestricted communication across multiple platforms.

Quiet is a free, open‑source messaging app that eliminates the need for central servers. Messages sync directly between devices over Tor, giving you full control of your data and communications.

💬 Peer‑to‑peer messaging without servers

🛡️ Built‑in privacy with onion routing

🌐 Cross‑platform support (Windows, macOS, Linux, Android)

⚡ Lightweight and community‑driven project

🚫 No reliance on Big Tech infrastructure

Perfect for: Users who want secure, private group or organizational messaging without depending on third‑party servers.

Etar is a free, open‑source calendar app for Android, designed as a simple and privacy‑friendly alternative to Google Calendar. It’s lightweight, modern, and integrates seamlessly with Android devices.

📆 Manage events and schedules with ease

🔒 Privacy‑respecting, no Google dependency

🎨 Clean, modern Material Design interface

⚡ Lightweight and fast performance

🌐 Syncs with CalDAV and other calendar services

Perfect for: Android users who want a simple, elegant, and privacy‑friendly calendar app without relying on Google.

Obsidian is a powerful note‑taking and knowledge management app that adapts to the way you think. It uses Markdown files stored locally, giving you full control over your data while offering extensive customization through plugins and themes.

📂 Local‑first: your notes are plain Markdown files

🔒 Privacy‑friendly, no forced cloud dependency

🧩 Hundreds of plugins and themes for customization

⚡ Fast, flexible, and extensible knowledge base

🌐 Cross‑platform support (Windows, macOS, Linux, Android, iOS)

🤝 Free for personal use, with optional paid sync and publishing features

Perfect for: Writers, researchers, and thinkers who want a private, customizable, and extensible knowledge management system.