You basically have three options for cross-platform developement (I'm assuming this is the goal behind your question) :
Use the widely-supported HTML(5) standard, create basic blocks (buttons, menus,...) looking exactly like the target mobile platform, and add custom features (location, camera) through JavaScript. The app looks and behaves exactly like native apps on each platform, but is actually just a webpage running under a custom wrapper.
This is what PhoneGap does, this is also what ShoutEm does, and probably also the case for Appsmakerstore (I'm not sure for this one).
Build a custom framework for each platform (you have to use lots of different languages, such as Java on Android, Objective-C on iOS, and so on) and maybe use a common language (JavaScript? Ruby? Python? Lua?), or a basic edition interface (a la WordPress or Drupal) to allow you to edit content easily.
Develop each app independently. You have to be ready to invest more time (and money) into that, compared to the other two solutions, but the user experience will in most cases be much more beautiful and consistent.
Basically, #1 is more than okay for simple apps, even though it can be a little bit slower then fully native apps. In recent news, Facebook just dropped #1 and went back to being mostly native.
I am not aware of anyone offering #2 and having great reasults for fully native, cross-platform developement, so you'd have to roll your own in this case.
In any case, you might also want to look at this question for a more in-depth review of the subject.