Build on existing app (to include in-app purchases)

We are looking to build on to our existing simple iPhone/iPad/Android app. Simple 'conversation card' style app. One question on each screen, swipe or tap logo to go to next screen). [login to view URL] Would like to add 'in-app' purchase options for additional 'sets' of conversation cards (see table topics app as a sample) We have 3 additional sets we would like to add as in-app purchase options. We supply artwork and text/logos.