I have been using imo application since one month.
Sometime the voice being not clear in the audio call.
The video call is very slow and the video is not clear.
In the video call one has to plugin the headphone or bluetooth other wise the call could not become efficient.
As I am using it for more than one month it is good but still there is lot of things which can be improve.
I like most in this application is its notification rington.