Any tips for app loyalty strategies?

Hey guys, I’m developing a new mobile app and retention is my biggest concern right now. I’ve read that offering a loyalty program within the app can really help keep users engaged, but I’m unsure where to begin. I’d like to find a user-friendly way to reward my app users that doesn’t feel spammy or complicated to implement. Ideally, I’d want something I can scale as the app grows. Does anyone here use a loyalty platform for mobile apps and have any advice on how to make it work well?