I have been playing a new-to-me incremental game (think Cookie Clicker) on mobile. It's called Magic Research and it is very good. It's available on both the Google Play and iOS app stores, and it costs a one-time fee of $4. There's a free demo on Android too.

Play Store: https://play.google.com/store/apps/details?id=com.mcolotto.magicresearchfull

iOS Store: https://apps.apple.com/us/app/magic-research/id1671272877

Android free demo: https://play.google.com/store/apps/details?id=com.mcolotto.magicresearch