I tried rebtel in the past, although I found it very cheap but the call quality was'nt good.

You won't know if the phone on the other side is ringing/busy or switched off, It always gives same ringing tone.

Currently using lycatalk:
Pros :
Call quality is awesome, it's like you are talking on local phones.
charges 1c/min.
nultiple numbers can use same account(but not at the same moment).
Cons :
You have to dial in number after calling there local access number or use Rajcanada's technique of adding pause while saving the number.
No App to call.

Try again with the updated app .. I am sure you would not be disappointed .

Thanks for sharing lycatalk .

-----------------------------------------------------------------
Fido.