You are downloading the Libby XAP file v220.127.116.11 for Windows Phone. Libby is a free and useful Books & Reference app: Libby is your mobile assistant for the online Librivox free audiobook library. You can listen any public book in the LibriVox system (yes it plays ... You can now download the offline XAP file to install & try it.
Download Locations for Libby 18.104.22.168 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 Libby XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.