Pro mode is no longer available in the Turf app!
Comes with Android version 0.6
Pro mode was added to Turf with version 0.6, 17 May 2011. It was needed since the satellite maps requires a lot of mobile data to download.
With pro-mode there is no map, but only a black background along with the zones locations.
Screenshot of Pro mode
Disappeared with Android version 0.9.9.0 (1.0.0)
Pro mode disappeared with the first version of "Supporters only" Beta version Version 0.9.9.0 which was released 2015-02-18. Version 1.0.0 was released 2015-10-18 and was the first public version where Pro mode was removed.
Map Cache replaces Pro mode
To reduce data traffic and to some extent save battery, there is instead map cache.