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Just found another that's pretty cool... FarmLogs. They have a full website that has a lot of move features for free. It does field mapping, rainfall amounts, activity logging, storage tracking, nitrogen management, seed placement, etc. Developed by a small company in Ann Arbor, MI. They seem like a pretty good group.
https://play.google.com/store/apps/details?id=io.trigger.forge633ed212c46d11e185cd12313d1adcbe