We wont go very far into buying and installing applications on your iPhone and Touch. Apple encourages this activity so they make it VERY easy. From iTunes, select the iTunes Store option along the left side. One of the options you will have is “App Store”. Clicking on this option give you a whole area of applications that will do about anything you can image… about.
Free and for pay options arranged into Business, Entertainment, Finance, Games, Photography, Healthcare, and many more…
Apple and their iTunes will happily accept your credit card for your chosen application. For now, most apps are rather inexpensive as programs-for-sale go.
Now, the Tips you came for:
If you own several iPhones/Touches, for now you can install a application purchased on all of the devices as long as they sync to the same iTunes account.
Different from iTunes music purchases, you can re-download applications. Just ‘buy’ it again, iTunes will recognize that you bought the app already and allow you to download without hitting your credit card again. This way, if you have multi computers all using the same iTunes account you can download and install apps to iPhones/Touches syncing to those computers. You can install which of your purchases you wish to, not all on one iPhone is required installed on another.
We will cover how apps are updated in an article shortly.