Nixie LiveWallpaper Trial is a free Live Wallpaper app developed by Rooty Pict for Android 9.0. The app features a retro-style clock display that allows you to choose between 12 or 24-hour format, and change the height and background of the clock.

The app is easy to install and set up. After installation, you can access the settings by going to Home > Menu > Wallpaper > LiveWallpaper > nixie. However, it is important to note that you may encounter errors when setting the wallpaper, which can be resolved by trying again or setting other wallpapers first.

Overall, Nixie LiveWallpaper Trial is a simple and straightforward app that provides a unique retro aesthetic to your Android device's wallpaper.