Here is the requirement:
Create a android app such that:
1) Allows to create cart offline
2) Should be able to order offline
3) At the moment phone comes in internet vicinity, it should be able to push the information to website
4) It should be able to sync the DB from website to local android, so that user can create cart
5) Should be able to recieve in app message in case items in cart is not available
6) Remember previous cart
7) Can create cart and store it for later usage
8) Should be able to get the delivery location as user registrated location by default. User can change the delivery location during cart creation
UI should be innovative and easy to use for user.
Above is main requirement. Please evaluate and come back if you can commit time.