UserGuiding - Create in-app experiences with the most straightforward product adoption platform — quick implementation, lasting user engagement.
John's Background Switcher - Switch backgrounds to trending imgur, reddit, tumblr threads
Usetiful - Fight user churn with great user onboarding. Interactive product tours and smart tips significantly improve your user retention.
Muzei - Muzei is a live wallpaper that gently refreshes your home screen each day with famous works of art.
Userlane - Digital adoption platform with interactive guidance for software applications allowing anyone to understand and master any software from the get-go.
Variety Wallpaper Changer - Variety is a wallpaper changer for Ubuntu which is featureful, yet slim and very easy to use.