Would it be offensive if I have a few good friends/acquaintances sign an NDA to beta test my app?

Hey – just to play it safe you might as well have every beta tester sign the non-disclosure agreement (NDA). It seems you have “a few good friends” who you trust more than your other “good friends,” but if you’re concerned about offending anyone then make sure everyone is held to the same standard. If you’re thinking of having an attorney draft your NDA then try out LawTrades. We offer free no-obligation price quotes so that you can see just how affordable it is for an attorney to draft your agreement (as opposed to a boilerplate, risky DIY provider).