I use a lot Jajah, and I can say even if the quality is perfect; I’ve been encountered 2 annoying features:

– Call back agent, who charge your call after 5 ringtones even if your friend didn’t respond (by harasing them via mail I got refund of 10€ for that)

– Limitation when changing your number:

Maximum number of changes per phone category exceeded allowed limit. Please contact support.

So, I cannot change my source number anymore… I will definitly quit this service, But I cannot find a good one similar and cheap.