Altering phone book numbers (Android)

I need a very simple mobile application for Android phones This application will alter all phone contacts which have certain patterns with new patterns because mobile operators changed their prefix codes. This alteration will change all mobile numbers by adding new digit. This will make mobile numbers 11 digits instead of 10. The solution should take care of numbers with code country and landline phone numbers Suggested algorithm: Count 7 digits from right and check the pattern of 3 digits if they match the pattern, if so replace those digits with the corresponding 4 digits This application is very simple and should not contain any bug I'll send the mapping patterns later and the initial layout image. Support Arabic and English languages