my i phone software does not support app

Latest version of iOS that will run on an iPhone 3g is iOS 4.2.1 per

http://en.wikipedia.org/wiki/IOS_version_history

If the app you are interested in needs a later version of iOS, you

will have to purchase a newer iPhone. Decision as to what versions

of iOS are supported are made by the developer of the app and not

by Apple.

To find apps for older versions of iOS (quote from someone else's

post but unfortunately I lost their user name - apologies to them)

iOSSearch - search the iTunes store for compatible apps.

Vintapps 3.1.3 - paid app

Apple Club - filter apps by iOS version.