shMessenger is described as 'ShMessenger Mobile is a free instant messaging client for mobile phones, which supports YMSG (Yahoo!), MSN and GTalk protocols. In just a few minutes, you can chat with your friends on Yahoo!, MSN or GTalk from your mobile phone' and is an app in the Social & Communications category. There are more than 50 alternatives to shMessenger for a variety of platforms, including Android, iPhone, Windows, Online / Web-based and Mac. The best alternative is Telegram, which is free. Other great apps like shMessenger are Jitsi (Free, Open Source), WhatsApp (Free), Hangouts (Free) and Zulip (Free Personal, Open Source).
Jitsi (previously SIP Communicator) is an audio/video and chat communicator with full encryption that supports protocols such as SIP, XMPP/Jabber, ICQ/AIM, Windows Live, Yahoo!, GTalk/Hangouts extensions, as well as OTR, ZRTP, etc.
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**: ...
Linphone is one of the most famous open source softphones in the world. It is fully SIP-based, for all calling, presence and IM features. Use Linphone for free, and enjoy its intuitive interface and advanced features with our free SIP service or with an existing SIP account.
Trillian is an instant messaging app that works on phones, tablets, and desktops while keeping your chats neatly synchronized between all of them! We think conversation should be easily shared between all of your devices, not trapped as text messages on your phone.