DistroHopper

DistroHopper is a home screen replacement for Android that can resemble a number of different Linux desktops, including Ubuntu’s Unity desktop, elementary OS’s Pantheon desktop and the Gnome desktop.

Features include a couple of different themes, a search feature which allows you to search from a multitude of different search sources (both local and remote), and customisation options.

An optional gesture lets you swipe to open your notification tray. If you choose to enable this feature, DistroHopper uses an Android Accessibility Service to open the tray for you — the only way a home screen app can do so. The Accessibility Service is only used to open the notification tray. It doesn't read any screen content or perform any other actions.