Drone Dodge and Crash the Drone
On Android these are hybrid games, basically a web game running locally in the Android Webview. Drone Dodge has support for Leaderboards on Google Game Servies where scores are listed. Logging in to Game Services is not mandatory so you can skip it if you want.
Crash the Drone does not include a Leaderboard because it is more skill oriented and the highest score is 100 which can only be achieved by knocking down all 15 drones in a game. This is very difficult to do. However Achievements are tracked on Game Services and can be displayed by pressing Achievements. Again it is not mandatory to log into Google Game Services unless you want to track Achievements.
The web only versions on Clay.io can be played on iPhones, iPads and other mobile devices as well as desktop and notebooks via web browser. Currently these do not offer Leaderboards or Achievements but plans are to offer them in the future. Again you may skip the Clay.io login if you want.