No — not on Android
Tampermonkey is on the App Store for iPhone/iPad. We did not find an official Android version on Google Play.
App Store
No Android version
Is Tampermonkey on Android?
About Tampermonkey
Tampermonkey is a widely popular browser extension compatible with all major browsers. It lets you customize and enhance web pages using userscripts—small JavaScript programs that add or modify features. Easily create, manage, and run these scripts on any website with Tampermonkey.