I attended Farmworks training this week. For about $250 you can get software to make your PDA into a credible GPS. You might also need a receiver. A bluetooth receiver for under $100 is a good alternative.
CCA, CPSS, CPSEC
Reared on a farm in Southwestern Illinois
Educated at the University of Illinois in Urbana-Champaign (1977)
25 years with USDA-SCS (NRCS since 1994)
Soil-Right Consulting Services, Inc. 2005 - 2015
RPM Soils LLC 2016 to present