Android and iphone app for it certification

Want to develop a mobile application (android and iphone app) for it certification mock exam. Mostly it will be multiple choice question. The question can have images for illustration. Single app will have an exam search option. There will be about 1000 different cert mock exam to choose from. Once selected, the selected exam will be downloaded to the device. Each exam might be priced different. There should be an option to add new exam or update questions in existing exam by the admin. At first I need high level quote and design