I'm not the original poster, but I believe the most important part is finding, creating and executing on the business model (value proposition, finding channels, CUSTOMERS), the coding is just a small part of the execution:
If your iOS app is just relying on the App Store as its channel, and the coding involved more than just writing to spec then maybe it's worth more than 5%, but the main value is in finding the spec, not coding it :) - if part of the value or the main part is having a good execution and user experience, it's also likely worth more than 5%, but it's maybe better for a VC-backed startup to just pay employees.
http://steveblank.com/2010/01/25/whats-a-startup-first-princ...
http://www.businessmodelgeneration.com/downloads/businessmod...
If your iOS app is just relying on the App Store as its channel, and the coding involved more than just writing to spec then maybe it's worth more than 5%, but the main value is in finding the spec, not coding it :) - if part of the value or the main part is having a good execution and user experience, it's also likely worth more than 5%, but it's maybe better for a VC-backed startup to just pay employees.