iOS app blocker that’s free or reasonable one-time purchase?

If you could help me find an app blocker I can set up to block social media for hours, not one that makes you take a breath then choose (one sec) I would be grateful! If you know it, please share the one-time purchase price because that’s the time-consuming part of trying to find one. Would love one for 40 bucks or less. I don’t do subscriptions.