I don't have an app for my site; the site is mobile friendly, and that's more than enough for me.

But I've recently discovered that I could use one new feature: a badge or widget that shows mobile users when there's new activity on a section of my site they want to watch.

I'm guessing this would require their phone to either log in to the MySQL database on my server, run a query, then show a number next to the icon with results. Or, it could simply access a PHP page that does the same thing. Either way, the program would need to store their username and password locally.

Being a total newbie to app design, I can't figure out where to start. All of the tutorials I'm finding are for writing apps, not badges or widgets.

Any pointers on where to get started?