What to say when he says he's not usually on the app much

He's telling you the app isn't his main habitat. He might check it sporadically, he might have a tendency to delete it and reinstall it, or he's just not the type to stay plugged in. The second layer is that he's pre-emptively lowering the expectation for response time so you won't think he's ghosting if he vanishes for three days.

This is not the same as him saying he's not interested in you. He's just being honest about his relationship with the platform. He might be very interested and also very scattered with push notifications. Read it as a logistics note, not a signal about you.

Your reply should feel like a shrug, not a vow. You're acknowledging what he said, maybe making a small joke about it or relating to it, and then continuing the actual conversation. The worst thing you can do is signal that you understand this app thing and you'll be patient and you're cool with waiting.

Instead, reply in a way that says you heard him and you're just going to talk to him. Don't ask him about his app habits. Don't promise to be patient. Just move forward naturally, like two people who might text at different speeds and that's fine.

If he goes dark for a few days after this, it's because of what he told you, not because he's lost interest. You've already replied. You don't need to send a second message asking how his day was or checking in. Let him come back when he opens the app again.

If he takes longer than a week to reply, it means the app priority is low enough that you should probably be open to other people. You can continue the conversation if and when he shows up, but don't hold your breath or adjust your life around his app schedule.