Options for International mobile number verification in Applications

hi guys

i was developing one android app, which needs the user's number verification before proceeding to installation. I tried a lot experiments and spend a lot time on internet to find an economical way for number verification. Here I am sharing my research result on the topic of international number verification. All you people are welcome to share your experience as comments. This is ascending List based on price,

Cognalys, Inc

Technology
Unlike all other methods ( self sms, sms, voice etc ) they use a unique idea of missed calls for verification.

Price
Xtremely cheap daily 500 verification free. Enterprises starts at $125

Integration
Easy integration ( plug and pla android library and API services)

Nexmo

Technology
SMS based verification.

Price
cheap 0.0080 $ per SMS (only 25 countries)

Integration
Easy to integrate APIs

Plivo. Inc

Technology
SMS based verification.

Price
Comparatively costly 0.65 $ per SMS

Integration
Easy to integrate APIs

FYI: i am using an enterprises plan from cognalys for my Android application( 10000 verification and 14000 user tries @ a prize of 125$ annually). Friends my suggestion is add your experience to this thread related with mobile number verification in your applications. So the other developers will get an idea about economical solutions.

— modified on Oct 31, 2014, 2:20:54 PM