Just because there are circumstances where presence of a condom makes the difference doesn't mean it does so in every case; the app would still get some people laid (and keep other people safer).
If one is going to be having sex outside of such a relationship (by which I had meant "when one is not in such a relationship" although I suppose it would apply to cheating too), one should be wearing condoms, yes? That's the part I was talking about, and I don't see how it's the opposite of what people should be doing.