You are downloading the ScreenRotation XAP file v126.96.36.199 for Windows Phone. ScreenRotation is a free and useful Productivity app: You need a shortcut for screen rotation settings on your start page? Here it is! Just download this app and pin it to your start page. ... You can now download the offline XAP file to install & try it.
Download Locations for ScreenRotation 188.8.131.52 XAP file
Note: To install it manually from an SD card, you should choose one of the server location above to get the offline ScreenRotation XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.