It'd be easier if you had some examples of what type of app(s) you want to make.
If you want to access fx. the mobile phone's camera, bluetooth, contacts, calendar entries, photo album etc. - then you probably need the developer's SDK, and to program it all in fx. Objective C for iOS.
But if you want something lighter, say, a small calculator, an app for displaying non-dynamic content etc., then Construct 2 could actually do the job for you.