What are some free basic mockups for prototyping Android apps?

Question

Android

I'm looking for a simple preferably free mockup for prototyping an Android app. It is desirable that there were sets of icons.
Ideally, the simpler the better, the main thing is that it is free and without complicated registration.

Answer 1

https://material.io/
Free. Without registering.

Answer 2

There are a lot of free solutions on the Figma website itself in the Community section. Just go to the preview you like and click Duplicate. - https://www.figma.com/community/mobile_design