You are downloading the IngTheremin XAP file v18.104.22.168 for Windows Phone. IngTheremin is a free and useful Music app: Virtual Theremin for Windows Phone 7 and 8.2D touch area is for manipulating sinusoidal sounds. X-axis is for controlling frequency, Y-axis is ... You can now download the offline XAP file to install & try it.
Download Locations for IngTheremin 22.214.171.124 XAP file
Note: To install it manually from an SD card, you should choose one of the server location above to get the offline IngTheremin XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.