iOS software

I need application for my iPhone that could RUN on background or while the phone is locked-- to operate without having to open the application. The application is about GENERATING and SAVING contact numbers based on conditions the user set. In the application main page there should be 3 text boxes. "Code" + "Length" + " Extension" Code: Is the prefix of the number like +963/ +9993 / +2233 ..... etc. Code is the same for all numbers in the list. Length: Represent the digits in the middle of the number. If the entered length is 5, it means the last number is 99999. if 4, then 9999 and so on. The application will find all combination between 0 and the maximum number. for example, From 00000 to 99999, or From 0000 to 9999. and so on. Extension: last digits in the number. the is a fixed number like the code. Example: Code=+9512. Length= 5. Extension=22. After clicking OK or generate or whatever. The application will generate the following numbers: +9512(00000)22 +9512(00001)22 +9512(00003)22 +9512(00004)22 ........ UNTIL ----> +9512(99999)22 So basically, there are 100,000 numbers. After those numbers have been generates, the application should SAVE them in iPhone contacts. The name of each contact is not an issue. Could be 00000 00001 00002 .... etc Now, due to computation limit in iPhone to handle such long series of calculations and processes, the application should work in stages. like 1000 numbers each 5 minutes or something like that. We can have discussion on that later.