I like how easy is was for me as developer of an Android app using MesiChat API (MesiBo) integration in my application; all code examples are available online through documentation so no problems here at least from this point! There's nothing bad about them except their price can be considered expensive if you're new or inexperienced with developing applications but they offer free trial period anyway which helps greatly when considering such things :) The best feature would have been more detailed tutorials regarding implementation process because there isn't much info out yet especially since we've just started our development project few days ago. It has helped us resolve some issues while implementing features into one android client where both users need access not only each other via messenger service provided by another party provider - also able to use audio/video calls functionality too.