How to optimize keywords on Google Play Store？

Relevant question. There are quite a few 'app intelligence platforms' that you can use for this. A simple google search will show some results - common tools that I have come across are: AppFigures, AppTweak, SenserTower, Data.ai....etc. Google's KW planner is also worth looking at. Most of them require a subscription fee though - You can use the trial plan but would advise to use it when you are serious with your app's growth