What it means he still has his dating app after two months

These are not the same thing. Some people don't delete apps because they forget. Some keep them as a safety net. Some haven't thought about it at all. But all of these point to the same thing. He hasn't decided you're worth closing the door on other options yet. Two months is when that decision usually gets made, even if it's just a quiet one. What matters is not whether he's swiping. What matters is whether he thinks about you enough to want to lock it down. If he still has the app, he doesn't think about it that way yet.

You need a straight answer about whether he's still using it and why. Your reply should ask that question without giving him outs. Then watch his response. If he gets defensive, that's information. If he says he forgot it was there, that's different information. If he says he likes you but isn't ready to delete it, at least he's being honest. The actual answer matters less than whether he's willing to give you one. A good reply puts him in a position where dodging the question makes him look bad, not you.

Don't ask about the app and then wait to see what he says before you decide how you feel about it. Tell him now that you're at a point where you need someone who's all in. Say it like a fact, not a threat. This does two things. First, it makes it clear this is not negotiable for you. Second, it tells him what your next move is based on his answer. If you need exclusivity after two months and he's not there yet, you need to know that now so you can decide what to do about it. A reply that doesn't include this usually means you'll have this conversation again in six weeks.