I have been looking at appcelerator it seems pretty fine! Without a doubt, one of the advantages of appcelerator is its support for multi-platform. I am interested in building a
My experiences with Appcelerator seem to suggest they are more of an iOS shop. Their toolset for Android is, IMHO, quite lacking. ADT supports visual UI building and debugging on device, which Titanium Studio does not. There has been a bug filed about this for several months now, and it continues to be delayed. If your focus is Android, use Google ADT or MOTODEV Studio for Android. These IDEs are quite nice and are used by professionals.
The above answer presents a great way to develop mobile apps. DO NOT COMPROMISE ON A HIGH-QUALITY USER EXPERIENCE.