Having a very similar problem to what is said above. Samsung Galaxy A5, Android Version 6.0.1 and Model number SM-A500FU.
As above I was able to play the beta no problem, but since live release the game does not appear in the app store, and direct link from the runescape website shows it as being "not compatible with this device", although I believe it meets the minimum necessary requirements.
Uninstalling the beta and clearing app store cache had no effect.
Would love to hear a response from someone as this has clearly been an issue for a long time
02-Feb-2019 01:58:22