nature. Stop fighting a losing battle. Learn how to block people and move on with your life. If you stop engaging they’ll get bored and leave you alone. They thrive on your reaction so stop giving them one.
The problem for developers is that the easiest way to stop engaging is to not play their games. They care about moderation because they want people to continue to play their game.
There are a lot of great suggestions here already, so I will just share Mini Review with you as a discovery tool. I like to use them because they have a lot of filters to help you find a mobile game. For example, here's their list for free, single-player, offline games with no ads or in app purchases, sorted by highest user score. They also have an app for both Android and iOS with the same info and filtering as the site.