Facebook Messenger
Free
Facebook Messenger is the official Facebook app that lets you have text conversations with all of your friends on the popular social network.
IM+
Freemium
IM+ supports simultaneously major IM services, including Google Talk, Twitter DMs, Yahoo!, AIM/iChat, ICQ, Jabber (and Slack through Jabber), etc.
Compare Kadu with alternatives
Compare Facebook Messenger and Kadu and decide which is most suitable for you.