"Recent iOS updates have led to TRASOL crashing on iPhones. We are actively working on an update to resolve the issue. Current workaround requires user going into main iOS settings and disabling location services for the TRASOL app. This will prevent TRASOL from crashing, but also prevents TRASOL from getting local weather services information and as a result limit its ability to automatically generate density altitude for your firing solution. Density altitude can still be manually entered. We are sorry for the inconvenience and will have an app update resolving the issue shortly."
It uses the Patagonia Ballistics engine, so yes it is a GREAT system.
Gustavo at Patagonia just does not make his system for anything but windows operating systems..so Nick at DT built program for other operating systems but utilizing the Patagonia Ballistics engine.