Actually review and remove the cheats when they are reported by users. Having a report button is useless if you never follow up or follow through on removing the cheaters. So many leaderboards where people don't follow the rules or find some other way to cheat to get a high score. Seems a lot of the cheats are the same people over and over, maybe you could also lock players accounts or ban them from appearing on the leaderboards if they are caught cheating more than 3 times or something like that. The lack of fairness really takes the fun out of the app.
