Can you install two versions of an app on the same iOS device?
It's not so much the name -- at least not the visible one, as an upgrade can change the visible name -- but it's the bundle identifier inside the app that identifies it and allows the OS to know it's supposed to perform an upgrade. The developer has to keep the bundle identifier the same in order to actually provide an upgrade and not a new app, so no, you're out of luck.*

*Note that there may well be some way to do such a thing if you jailbreak your device, but I have no firsthand knowledge of such.