I think it has become a massive topic - as the skills required are somewhat different than web pages. I have been "investigating" for some weeks now and suprised at the depth and range of the topic.
Marketing, programming the different Operating Systems user interface, use of third party compliers and development tools such as Titanium ( which was actually the prompt to mke the post as it seems buggy ), interface into backend servers.
For example at the moment I am looking at -
Do you use the latest Operating System versions or the version that is on most phones, i.e is everything backward compatiable for a particular operating system.
Is is better to have the database ( if needed ) on the phone rather than an external server ? If so what is the practical limit on size ?
What are the operating systems available and on whose phones do they run - guess that should have been the first question !
I am not talking about just the dreaded iphones here - but the creation of applications across a range of operating systems.
Currently also working on/learning Google Maps V3 which seems to be designed for mobile apps.