Also consider dividing the teams by roles, with each member doing one or more roles:
Integrator (keeps the current version of the app, merges in new screens & art and copies in new procedures using the Backpack, broadcasts new baseline versions)
Artist (develops graphic and sound files, sends them to the Integrator)
Coder (copies the baseline, adds features to it, sends it back to the Integrator in an .aia export to merge into a new baseline).
Tester
ABG