hello, i am happy that i am getting this opportunity to work on this project, i understand your idea about on demand services apps, and i have good expertise and understandings with existing on demand services apps, like BizzBY, TryHouseCall, Handy, TaskRabbit, and HomeJoy. so let me explain you in depth how actually these system work.
there are 3 roles in this system, ADMIN, customer, and service providers, admin can set categories for service providers like: (Handyman ,Plumbing, Electrical, Maid, Carpet Cleaning)
service provider and customers can create their account and login to apps,
A customer can login in app, and choose what he want to do and then look for service provider, he will see all registered service provider with their ratings and profiles, customer can schedule an appointment with service provider for Now(current time) or for future date. service provider will see his request and can accept if they can do this job via app.
service providers will have a schedule calendar in their apps that will show their timing and to set appointments in it automatically and it will make sure no 2 appointments collapse each other at same time.
customer can see service provider arriving on map in his app, and when reached he can say job started and app will calculate total time, and when job finished service provider can send invoice to customer and customer can pay via app, and service provider will receive payment confirmation, and then both can rate each other.