The app is totally safe to download. RDesign is the creator of Kreis Tuning that can be found in the Lifestyle category. According to the latest data, the tool is rated 4.6 on Google Play.
The most recent release was on Oct 20, 2020 and this application was downloaded and installed by over 100 users. It's free to get the installer of Kreis Tuning, also, you can have a look at users' reviews on Droid Informer. The app runs on Android 5.0 and higher.