I need to work on a project in web-application but really need to have it as a mobile application because the target environment make use of phones more than laptops, though also planning on having the web application later. The application is like a social-network site but not for social contact. It has basically 2 different kinds of users (Common users & Professional users). Every user must be able to create his profile, and the common users must be able to follow professional users (just like twitter).
My questions are:
Can I just have it as a web application and then look for a way to convert it to a mobile application as I only have experience with web but not with mobile applications?
Taking facebook as an example, does it has a separate mobile application or just convert the web application to mobile app?
What kind of database(relational or non-relational) is suitable for this kind of task.
Thank you.