I have now made available the spotter application under the GNU GPLv2 license, head over the spot calculator page for some background story and a link to download the latest version.
There have been a few requests to deploy the spotter, and I enjoy giving back to the skydiving community! Would love to hear from you if you have tried, installed, or made modifications!
update 3/7/13: Thanks goes out to Tyson and his gang at Skydive Snohomish for finding and reporting an error in drift calculations when north was reported at 360 instead of 0 degrees. The download link has been updated with the fixed version 1.2.2