Communication
34 apps
Messaging is where open source matters most, because you can check how your messages are handled. Signal publishes its Android client and uses end-to-end encryption by default. Telegram's Android client is open source too, but regular chats are encrypted only between the app and Telegram's servers; only secret chats are end-to-end.
Aster Mail48Kotlinupdated todayPrivate, end-to-end encrypted email with post-quantum protection, PGP, aliases, and custom domains.Google PlayF-Droid 1.0.11
ChatSecure1.1kJavaarchivedA private and secure messaging app for Android and iOS.
Crisis Connect10Kotlinupdated todayAn open-source, offline-first mesh messaging app over Bluetooth built with Kotlin and Jetpack Compose.Google Play
FairEmail4.7kJavaupdated todayA fully featured, privacy-friendly open-source email app for Android.Google PlayF-Droid 1.2338
httpSMS6kGoupdated 9d agoConverts your phone into an SMS gateway with a simple, programmable API.
IRCCloud314Javaupdated 5mo agoThe official open-source Android application for IRCCloud.com.Google Play
Jev Chat Assistant7.8kKotlinupdated todayA chat copilot that reads the open QQ, X or Feishu/Lark conversation via the accessibility service, suggests three replies using your own LLM API keys, and fills the chosen one into the input box without sending.
K-9 Mail14.1kKotlinupdated todayAn advanced, open-source email client for Android.Google PlayF-Droid 23.1
Kabootar2Dartupdated 1mo agoAn offline mesh messenger that relays chats phone-to-phone over Bluetooth and Wi-Fi, with no internet, servers, or SIM.
KissProxy121Javaupdated 12y agoAn NIO-based local HTTP/HTTPS proxy for Android.
Kontalk Messenger575Javaupdated 3y agoThe official Android client for the Kontalk instant messaging network.
KouChat100Javaupdated 5y agoA serverless LAN chat application for local network communication.Google PlayF-Droid 1.1.1
MaterialQQLite128Javaupdated 11y agoA Material Design-style client for the QQ messaging service.
Messaging (Odoo)62Javaupdated 10y agoThe official mobile messaging client for the Odoo platform.
OTP Relay0Kotlinupdated 1mo agoForwards one-time passcodes to one chosen contact, for a set time, entirely on the phone: no server, no SMS gateway, no network calls.
ProxyDroid2.6kKotlinupdated 5mo agoA global proxy application for Android devices.
QKSMS4.6kKotlinupdated 3y agoAn open-source replacement for the stock Android messaging (SMS/MMS) app.Google Play
Rocket.Chat46.3kTypeScriptupdated todayA self-hostable, Slack-like online chat platform.
RTranslator10.5kJavaupdated 3d agoThe world's first open-source simultaneous translation app.
Signal29.5kKotlinupdated 1d agoA private messenger for secure calling and messaging.Google Play
Silence1.1kJavaupdated 5y agoA privacy-focused SMS/MMS application that uses end-to-end encryption.
SMS Resend2Kotlinupdated 2mo agoAndroid app that forwards incoming SMS messages to a Telegram chat through the Telegram Bot API. No bot server required.
surespotJavaA mobile messaging app that secures messages with end-to-end encryption.Google Play
TeamTalk (mogujie)735Javaupdated 11y agoThe official Android client for the mogutt TeamTalk service.
Telegram30.1kJavaupdated 2d agoThe official, open-source Android client for the Telegram messaging service.Google Play
Tint Browser223Javaupdated 10y agoA lightweight, open-source web browser for Android 4.0 and above.
Tutanota8kTypeScriptupdated todayAn end-to-end encrypted email client focused on security and privacy.Google PlayF-Droid 360.260922.0
Ulangi455TypeScriptarchivedA language learning app that uses spaced repetition and other popular methods.
VideoFly21Javaupdated 11y agoA video calling app that allows you to multitask during a call.
WeChat (Clone)5.5kJavaupdated 8y agoA clone of the WeChat application.
WiFi Walkie Talkie162Javaupdated 1y agoTransmits audio over a local WiFi network, acting like a walkie-talkie.
Wire255Kotlinupdated todayA secure messenger offering end-to-end encrypted communication.Google PlayF-Droid 4.35.1
Yaaic338Javaupdated 4y ago"Yet Another Android IRC Client" for connecting to IRC networks.
Zulip403JavaarchivedThe official Android client for the powerful open-source group chat platform.