Imo is the video calling app that we can use also in 2g network and also the app is in betwwen 10 mb and also it takes very less mb by using this app.
Other apps are even dont open or runs in very in 2g .
I have been using app from last 6 month and find it banificial.
Many of my friends are also use this app.
We also can share photo and and messages in this app that the another facility in this app.