Mobile application (Android) and website. How?

Question

Android

There will be a site where you can register (something like social. Sit down). - In short, it should be like on any facebooka's and vkontakte - the site and the application are a single whole. In vk and fb - this is somehow understandable, there is an API there. We don't have anything right now. Where and how to start?

Answer 1

start with API

Answer 2

Is it necessary? If you make an application, then you can not "offend" users of a particular mobile OS. This means that you will need to make at least 3 applications: for iOS, Android, Windows Phone. If you still need an application, then you can first launch the site, but make a mobile version or limit yourself to adaptive design. And only then calmly deal with API and applications.
Vkontakte also did not immediately have an application. I remember using the mobile version, which, by the way, was and remains more functional than the application (for WinPhone). Another plus - you can switch to the full version of the site at any time.