A FreshBooks account is necessary to use Book Keeper, if you are not a FreshBooks user sign up for free now.
OTA install here: BookKeeper.jad
Simply point your device to the above URL, or visit http://www.bookkeeperapp.com on your device and you’ll be presented with an install link.
Desktop Manager install here: BookKeeper.zip
Download the zip file and follow the regular desktop manager process for installing BlackBerry applications!
To use Book Keeper, simply enter your FreshBooks account credentials and let oAuth do the rest. If you have any specific questions, see the support and contact pages or follow Keone on Twitter and message me there!