Gray dot has disappeared.
A gray dot showed up on my iPad screen and touching it took me from any of my games or apps to the Home Screen. It has disappeared just when I was enjoying what it did. How do I get it back?
iPad Air (3rd generation)
Perhaps you refer to Assistive Touch.
To enable/disable this feature:
Settings > General > Accessibility > Touch > AssistiveTouch > Assistive Touch - set to ON or OFF as required
Additional information about Assistive Touch can be found within the iPad User Guide: