We have a website where subscribers book appointment with service providers like electricians, plumber etc. I would like to build an app for the service provider so he can;1. see the list of appointments, go into each appointment and mark it as done, reschedule, cancel, no show etc2. enter new appointment detailsSo the flow is like thisLogin > using mobile number/ email id the user is linked to his web accountDisplay three buttons > Appointment Schedule > New Appointment> Call The Call CenterNow the app should be synched with our website database account of the subscriber for the details to be popped up.The bid should involve ensuring smooth running of app on latest to previous versions of iphone and android and further upgrade for the next 1 year for bug fixing and version upgrades of android and IphoneThanks