Free messaging without SMS fees, web sync, and multimedia sharing, supporting group and video chats, available on iPhone, Android, and desktop.

Hangouts is a messaging app that lets you send and receive messages, photos and more, and even start free video and voice calls – one to one or with a group!

Wire is the most secure collaboration platform featuring messenger, voice, video, conference calls, file-sharing, and external collaboration –all protected by the most secure end-to-end-encryption.

Jami (formerly GNU Ring, SFLphone) positions itself as a potential free Skype replacement

Digital workspace organizer that allows you to unify many applications, all in one place. Perfect for those who care about productivity while working with many business and personal apps.

Secure messaging, free calls, group chats up to 250, emoji reactions, disappearing messages, low-cost international calls, rich media and community channels.

Offers group video calls, voice calls, and instant messaging with photo sharing, real-time notifications, and location mapping for seamless connectivity.

Franz is a free messaging app / former Emperor of Austria and combines chat & messaging services into one application. Franz currently supports Slack, WhatsApp, WeChat, HipChat and many more. You can download Franz for Mac, Windows & Linux.

Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].

Protect your communication in transit and on your phone. Silence (formerly SMSSecure) is a full replacement for the default text messaging application: all messages are encrypted locally and messages to other Silence users are encrypted over the air.

An open-source decentralized and encrypted messaging app even without internet connection via Wi-Fi and Bluetooth. Messages are stored securely on your device, not in the cloud. Connect directly with nearby contacts - no Internet access is required.

Secure communication for individuals, teams, and large organizations.

An alternative Telegram client based on TDLib, with higher speed, slicker animations and experimental features.

Open source Jabber (XMPP) client with multi-account support, clean and simple interface. Being both free (as in freedom!) and ad-free, Xabber is designed to be the best Jabber client for Android .

Ripcord is a desktop chat client for group-centric services like Slack and Discord. It provides a traditional compact desktop interface designed for power users. It's not built on top of web browser technology: it responds quickly to input, sips gently from computer...

Plus Messenger is an messaging app that uses Telegram 's API. Plus Messenger has all of Telegram's features plus themes. Plus Messenger is free for android devices.

Messenger Lite is a fast and data-efficient messaging app to reach the people in your life.

Pinger lets you text and talk free with the people you care about most, anywhere on the planet. Tap a picture and you'll see all of your communications—texts, pics, calls, voicemails—all in one place.

Dasher lets you do more than just text message. It's messaging with benefits:

Free calls and messages.

Lightweight messenger for Android optimized for 2G and unstable networks, offering free voice, video, and group calls, reduced data mode, and SMS Insights.