You are downloading the MyChem XAP file v126.96.36.199 for Windows Phone. MyChem is a free Education App: Helpful guide for Chemistry Students. Includes Periodic Table, Cation Tests, Anion Tests, pH Scale and Chemistry ... You can now download the offline XAP package file to install & try it.
Download Locations for MyChem 188.8.131.52 XAP file
To try to install it manually from an SD card, you should choose one of the server location above to get the offline MyChem XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.