A free program for Android, by Galaxy studio apps.

Assistive Touch: Screenshot is a floating tool on your phone’s screen. You can use its various tools to perform different functions, like locking the screen, taking a screenshot, and more. It can be used on tablets as well.

This app is developed to assist people with disabilities to use their mobile devices more easily. 

Assistive Touch: Screenshot has many functions that can be used with ease. You can customize the color of the icons and themes in this app, and there are many themes available. You can change the color of the icons and themes, and the background color. You can choose from the icon pack that is available in this app or you can choose your own icon pack from the Android app store.