I want to put icloud app on to iPhone 3GS?

I have been given iphone 3 gs but all apps seem to want i.o.s 5.0 at least.Is there a way around this problem?

Nope. It isn't possible to download older versions of ios or the iCloud, and I'm assuming your iPhone isn't compatible with the new operating system so it's late for you buddy.

You could upgrade to to iOS 6.1.6 & run iOS 5 apps just fine.

Or you could download apps on the computer and see if the app has a last compatible version by trying to download on the iPhone afterwards