Top free Open Source android apps
K-9 Mail
K-9 Mail is an open source email client with support for multiple accounts, search, IMAP push email, multi-folder sync, flagging, filing, signatures, BCC-self, PGP/MIME & more!
Tutanota
The open source app Tutanota enables you to send end-to-end encrypted emails to anybody with a tip of your finger. Even emails that are being sent without end-to-end encryption and all your contacts are stored encrypted on the Tutanota servers.
Firefox Focus: The privacy browser
Browse like no one’s watching. The new Firefox Focus automatically blocks a wide range of online trackers — from the moment you launch it to the second you leave it. Easily erase your history, passwords and cookies, so you won’t get followed by things like unwanted ads.
Rocket.Chat
Rocket.Chat is a free and open source team chat collaboration platform that allows users to communicate securely in real-time across devices on web, desktop or mobile and to customize their interface with a range of plugins, themes and integrations with other key software.
Timber Music Player
This a material design music player with Gestures for track switching, LastFM scrobble, Chromecast support, Android Wear and Android Auto support, Dark theme and UI customisability.
andOTP
Android OTP Authenticator
andOTP implements Time-based One-time Passwords (TOTP) like specified in RFC 6238 (HOTP support is currently in beta testing). Simply scan the QR code and login with the generated 6-digit code.
VLC for Android
VLC media player is a free and open source cross-platform multimedia player that plays most multimedia files as well as discs, devices, and network streaming protocols.
Orbot: Proxy with Tor
Orbot is a free proxy app that empowers other apps to use the internet more securely. Orbot uses Tor to encrypt your Internet traffic and then hides it by bouncing through a series of computers around the world. Tor is free software and an open network that helps you defend against a form of network surveillance that threatens personal freedom and privacy, confidential business activities and relationships, and state security known as traffic analysis.
Lean Launcher
It is an open source, lightweight mobile launcher.