If you imagine the mobility, smartphone, iPad, Android tablet being represented as a map of a generic metropolitan area, then I suggest that there is a new “App builder” website springing up an every street corner.

So after tackling the cloud infrastructure, delivery model and programming language in the Saas_Class, it seems appropriate to look at where the rubber ultimately meets the road in mobility the end-user experience — THE APP. No matter how cool, scalable, well-engineered or valuable your cloud application is on the backend, if the app sucks, you are dead in the water.

Over the next few weeks I will be building apps on some of the free or low-cost app building sites. Here are a few of the things I will be looking for:

• HTML5 versus native app building
• iOS vs. Android native app
• Integration with other platform apps and design guidelines
• Ease of use
• Ease of installation
• Sophistication of tool set to build a decent app
• Cost. If these app building sites are free, where is the money made? Has to be some monetization angle.

Here is a preliminary list of sites: Mippin, Anypresence, The Appbuilder, MoSync and WebMobi. Other sites may be added as discovered.

Now deciding on what the app will do is the next thing. It will be simple – the goal is to evaluate the tools not my application creation and design skills.

CHALLENGE: If you suggestions for app building sites or an application to build, leave it in the comments.