Are you wondering if a particular app will work on your iPod Touch? The iTunes Store actually tells you, but not in a very prominent place so it’s not obvious unless you look closely.

Every iPhone and iTouch runs a version of iPhone OS. It’s the software that runs “behind the scenes” to show you the home screen with the list of your applications, to let you install and delete apps, and to do all the other bits of housekeeping that you don’t see. Sometimes you need to know what version of iPhone OS you are running – here’s how to find out.

Using a web app with your iPhone or iPod Touch is easy – you just go to the web page for that app. The trick is knowing how to make the app appear on the main screen like other apps. Here’s how to install a web application so it works just like a normal iPhone/iPod Touch application.

For regular iPhone and iPod Touch Apps you purchase and download them from the iTunes App Store. You access the App Store from your iPhone or from iTunes on your computer and select and download the app you want. So what’s different about a web app and why does it matter?

Guest Post: this is a guest post from regular commenter Israel Torres. I spend hours a day staring at my iPhone checking out the latest and greatest apps that suit my needs or simply take my fancy. This is no simple task when using the iPhone, it’s usually simpler to browse on websites that are