Speak Messenger is described as 'enables you to send and receive Texts, Images, Voice Recordings and Videos in less than 100 milliseconds. Why Switch to Speak?' and is an app in the Social & Communications category. There are more than 10 alternatives to Speak Messenger for a variety of platforms, including Android, iPhone, Android Tablet, iPad and Windows. The best alternative is Telegram, which is free. Other great apps like Speak Messenger are Signal (Free, Open Source), WhatsApp (Free), Hangouts (Free) and Zulip (Free Personal, Open Source).
Signal is a messaging app with an unexpected focus on privacy, combined with all the features expected from a modern IM app. Signal has received a lot of praise from all around the world for its security and privacy-respecting technologies.
WhatsApp is an iPhone and Android messaging app which allows you to exchange messages without having to pay for SMS. In addition to basic messaging WhatsApp users can create groups, send each other unlimited images, video and audio media messages.
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]. [Note] **You can download the compiled apk for free from F-Droid**: ...
LINE is a Japanese proprietary application for instant messaging on smartphones and PCs. Line users exchange text messages, graphics, video and audio media, make free VoIP calls, and hold free audio or video conferences.
ChatSecure is a free and open source messaging app that features OTR encryption over XMPP. You can connect to your existing accounts on Facebook or Google, create new accounts on public XMPP servers(including via Tor), or even connect to your own server for extra security.