There are other apps like Apk Muzzle but the app to whom removes ADs/permissions often crash or are unusable.
Apk Muzzle uses a technique that generates more stable apps and without the ROOT privilege.

Since Apk Muzzle modify the original apps I decided to release the source code on GitHub (Apache License 2.0) so more experienced users can check how new apps become modified without introducing malicious code.

https://github.com/simoneaonzo/ApkMuzzle

Apk Muzzle (it's free and always will be free) is still a young project and with a very bad graphic but I'm interested to improve it: mail me for any doubt!

Within the application you can make a donation... it's always appreciated!