I have installed Skype on my Android phone and am using it to make International calls, but I don?t think it is the best VoIP service out there for Android.Although the rates are cheap compared to those of traditional PSTN or GSM calls Skype does not offer good network optimization and a lot of mega bytes are used up for my "free" calls.Is there any other alternative app on Google Play which optimizes network and has better unit call rates?