How to Install Jar / Jad File ? Download and install: JAR File - Try first! JAD File Download JAR application file to your PC and transfer to your memory card or phone manually.If that doesn't work, try to download and install the .JAD file. The file(s) can either be installed from the PC using the phone manufacturer software,or be transferred to the phone using Bluetooth, a memory card or a data cable. Important Information: This application is free of charge and free to download because it is ad sponsored.In order to play the application your mobile must access the internet using the phone data connection.