Always On is a free Android app developed by sengpedman that prevents your screen from turning off. This app is particularly useful when you are making demos or using an app that doesn't require much activity but you don't want the screen to turn off.

The app has a widget control on the home screen that allows you to turn on or off the screen stay awake mode. Additionally, the app offers options for full bright or dim screen as per your choice. If you are worried about battery life, the auto-close option of the app can be enabled to automatically close the app when your device's battery is running low. However, it is important to note that keeping the screen always on can cause the battery to drain faster.

Overall, Always On is a simple and useful utility app for Android that can help you keep your screen awake when you need it.