You are downloading the UniShare XAP file v0.9.3.3 for Windows Phone. UniShare is a free and useful Social app: Get sharing across multiple networks from your Me Tile back on Windows Phone 8.1 with UniShare!Unishare not only integrates into the Me Tile ... You can now download the offline XAP file to install & try it.
Download Locations for UniShare 0.9.3.3 XAP file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline XAP File To Install It Any More.
To try to install it manually from an SD card, you should choose one of the server location above to get the offline UniShare XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.