KEY Video Çözüm is a free Android app designed for students to help with their exam preparation. Developed by FERNUS, this app provides solutions to all the questions in the book. The app is updated regularly as more solutions are added.

The app is user-friendly, and it is easy to navigate. You can search for a specific question or browse through the solutions. The app is designed to work offline, so you can access the solutions anytime, anywhere.

Overall, KEY Video Çözüm is a great app for students who need help with their exam preparation. It is free, easy to use, and regularly updated. However, it would be nice to have some additional features such as explanations for the solutions.