Killer App for IOS & Android

I want to develop a simple stop motion app for students age 8 to 14 with the following specifications:

1) User-friendly UI with well designed icons.
2) The ability to add and upload different backgrounds.
3) The ability to animate 10 different stick figure sprites.
4) The ability to unlock and purchase more sprite packages as an IAP.
5) Here is an example of what I need...
http://pivot-stickfigure-animator.en.softonic.com/
6) The app should include all of the abilities of the example above. Some should be locked for the free version and unlocked for if purchased as a IAP.
7) The app should be able to save and send recordings to Facebook.
8) The final product needs to be completed in 3 weeks.
9) I will provide more detail specifications via skype.


Look forward to hear from you.
Hardi