CheckMobi - Cheap phone verification with sms or call ID

SMS verification Caller ID => You call a number that does not answer the phone but verify your number (can be done automatically with Android) Reverse caller ID => A number call you (for not even a second so you don't answer) and you have to under the 4 last digits of the caller number to verify yours The cost for one number verification is about 0.015 cent which is drastically cheaper than anything else.