1.  MapShots which is now dead.  Excel a lot, Climate, REAP harvest app.

2a.  Pick an application boundary to get an area.  Crop zone or field (are you going to shut off your lime spreader over a waterway or grassed terrace?) or multiple fields/cropzones or parts of a field, pick by make a polygon or pick by type in an application area or check a box on a list.  Or just shove in a single data point to any field/crop zone if you are getting VR stuff from another application, you can assign total use to a field or cropzone for recordkeeping purpose.

2b.  Split out costs by share/participant/field, if you have multiple owners or operators.  Assign different prices to different participants (like the retailer, some participants pay at different times of the year or make a decision to add a product later in season at a different cost, etc)

2c.  Pre-season planning functions (more than one plan, even) vs actual accomplished operations.

2d.  Reporting functions - how many units of product needed or used, reconcile between planned and actual, reconcile after the fact to match up the used product vs inventory to spread out inventory losses (spilled UAN out of a hose at the field type thing vs. what the flowmeter reads)

2e.  Some way to match up yield monitor yields with grain cart weights and a phone app to manually record or scan elevator tickets to digitize the paper which goes everywhere in everyone's pocket

3.  JD/Climate is nice, i don't think absolutely mandatory up front but standard in the industry.  I can manually transfer to accounting if I have good enough reporting functions.

4.  Sure.

5.  MRTN, a few rules of thumb (bushels per 1K seeds of corn planted), nutrient budgets (soil test vs applied nutrients vs imputed removal vs next soil test)