Hi, first of all i'd like to introduce myself. I'm an engineer from Spain who has been developing applications for iOS and Android for the past 6 years. During this period of time, i've done many apps with similar functionalities to the ones you have described.
I'd like to take a peek at your desings to ensure the duration of the project. I'm a very structured and quick developer. This, will allow us to make the next stories really fast.
I hope we can work together. If you have any doubts, please let me know. Best wishes,
Luciano.