You are downloading the Double Pendulum XAP file v220.127.116.11 for Windows Phone. Double Pendulum is a free and useful Education app: This is a realistic simulation of a double ... You can now download the offline XAP file to install & try it.
Download Locations for Double Pendulum 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 Double Pendulum XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.