You are downloading the Save to Instapaper AppXBundle file v2015.407.27.4111 for Windows Phone. Save to Instapaper is a free and useful Productivity app: You can then use a shared contract feature to save to Instapaper articles you want to read ... You can now download the offline AppXBundle file to install & try it.
Download Locations for Save to Instapaper 2015.407.27.4111 AppXBundle file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline AppXBundle 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 Save to Instapaper AppXBundle file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.