This application allowes the user to change wallpapers on his/her phone. You can push wallpapers from your computer to an online WebApi which is access by the phone application. The source code of the API is in tkoppop/Andriod-Wallpaper-Engine-API.
What the code does: It uses the api call with the key "tkoppop@Wallpaper@Test@App" to the online api where it stores a bunch of photos. The application cycles through the folder, adds a thumbnail per photo, adds a title, and allows the user to scroll through the all of the images in that api. Once a photo is selected, users have the option to set the photo as their lockscreen or homescreen. They also have the option to download photos from the api onto their phone.