jTalk is described as 'Full-featured XMPP messenger' and is a Group Chat in the Social & Communications category. There are more than 50 alternatives to jTalk for a variety of platforms, including Android, iPhone, Android Tablet, Windows and iPad. The best alternative is Telegram, which is free. Other great apps like jTalk are Signal (Free, Open Source), Element (Freemium, Open Source), Jitsi (Free, Open Source) and Tox (Free, Open Source).
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.
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.
An alternative Telegram client based on TDLib, with higher speed, slicker animations and experimental features. The goal of Telegram X is to reinvent Telegram and explore new frontiers in speed, ease of use, quality of animations and all other aspects.
ICQ is one of the oldest instant messengers. First developed by the Israeli company Mirabilis, sold to AOL, sold again and currenly owned by the Russian "mail.ru" group (known for one of the largest social networks).