I've just begun coding with Titanium to create an iOS app, and so far so good. The fact it uses JavaScript, meant I could get an app working incredible quickly.

I've just begun coding with Titanium to create an iOS app, and so far so good. The fact it uses JavaScript, meant I could get an app working incredible quickly. Even, if you are only developing for iOS or Android, I think that Titanium would help you a lot if your Java or Objective C knowledge is minimal (like me). It depends what you're comfortable with I guess. I'd second the point that Titanium isn't 100% write-once, run-anywhere. You'll certainly get a lot of reuse between your app for iOS and Android if using Titianium, but you'll have to tweak your code for each platform. I'm still a big fan however. I tried writing an app using JQuery Mobile, with plans to deploy within Phonegap. To be honest, the performance just isn't good enough. Since Titanium builds the app using native components, then it's so much more slick. I do love JQuery Mobile still however, and will definitely keep what I have for the actual Mobile Web UI. NB. Titanium also seems to compile to a Mobile web version, but I couldn't get that working. I might look into that more in future.