We are currently aiming Construct 2 at games, so there are some simple features like the two form controls but not much for apps right now. It's something we'll be looking in to in future.
Reading/writing files to disk generally isn't allowed in a browser, although there are some new HTML5 features that allow writing files to isolated storage. There's also the WebStorage plugin in C2 you could try out. Also, ini is a really old and long obsolete format from Windows 3.1 - I'm surpised it's lasted as long as it has! If we added equivalent features it would surely be XML.
In other words, app development in a browser is probably a little different to what you're used to, and we're missing some features right now, but we hope to patch it up soon.