ATAK Fans the much awaited Fire Area Survey Plugin has been posted as a beta plugin at tak.gov.
Here is a video on how it works and a getting started document is in the training folder at maps.takserver.us
You can use this tool to automatically create a shape from a KML as well and calculate acreage. I will make a video on how to do that soon. As an example an IAA/ISR ship posts a KML you can change that into an ATAK shape
Hoping its on the playstore soon but until then if your a gov employee you can register at tak.gov and get it there.