Android Question Database for Android, iOS and Windows

Never created a database before. Below are the requirements and what I'm able to work with:

1. The database needs to be accessed from Android, iOS and Windows. If it can be accessed from a browser that would be great too.
2. I don't have a dedicated server but have a Windows hosting plain from Hostgator.
3. I have options for PHP, ASP.net and SQL.

Can someone recommend a specific database for the information above? I've seen options for B4J, RDC, JRDC, DBUtils, etc. It's a little confusing and I'm hoping someone can point me in the right direction.