You are downloading the Calculus Test XAP file v18.104.22.168 for Windows Phone. Calculus Test is a free and useful Education app: MindBrainer presents: Test yourself on Calculus! Train your brain, make yourself awesome "human ... You can now download the offline XAP file to install & try it.
Download Locations for Calculus Test 22.214.171.124 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 Calculus Test XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.