I find it hard to keep track of the latest games, apps, trends etc and so rely on the internet, reviews and websites like CommonSenseMedia to guide me. I find CommonSenseMedia to be a fantastic resource, it's not overzealous or too conservative, I find it to be pretty fair and objective. Plus you get three recommendations from CSM, parents and kids.
Re TikTok and many other games/apps that have chat features, they come with a 18+ recommendation, simply because it's too risky having a chat feature where strangers can chat to your kids. There are various safety features, but IMO it's not worth the risk.