文系理系診断 is a free Android app developed by Testii that helps you determine whether your thinking style is more aligned with humanities or science. The app presents 15 random questions and psychological tests to diagnose your thinking style. You can use it to test yourself, challenge your friends, or use it as a conversation starter. Moreover, the app is equipped with a feature that allows you to play tests posted on the Testii website.

The app is free, but it displays ads to cover its costs. Testii aims to provide free apps to users while relying on ad revenue. The app does not require any personal information or data to operate.

The app is a great tool for those who want to learn more about their thinking style and explore their strengths and weaknesses.