You are downloading the pin.it APPX file v188.8.131.52 for Windows Phone. pin.it is a free and useful Social app: Pin.it is the most full-featured Pinterest app for Windows Phone • Full-featured - If you can do it on the Pinterest website, you can do it ... You can now download the offline APPX file to install & try it.
Download Locations for pin.it 184.108.40.206 APPX file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline APPX 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 pin.it APPX file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.