I have android app that contain some premium features, now when user click the premium button my app will open my website and user can register and pay login user and password using paypal from website.
i want the payment process to be more comfortable, so want when user click on premium button from my app to do following steps:
1) Display page that ask user to insert email and password and verify the email is correct by send him email code, in the page will appear the price and payment button
2) when click payment button app will verify email and password and email code are correct if yes then will complete the payment process
3) App will send the register details to my web service (located in my website) and will add the registered user and password to my database and will send the payment status if success or not to the web service as well (web service is already exist and I will provide it so you will not need to implement the register to my DB)
4) if payment success will login to app