You are downloading the Periodical XAP file v188.8.131.52 for Windows Phone. Periodical is a free and useful Books & Reference app: *Updated for windows 8.1*A great FREE periodic table of elements reference application. Browse the periodic table in portrait or lanscape ... You can now download the offline XAP file to install & try it.
Download Locations for Periodical 184.108.40.206 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 Periodical XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.