We have built the Farmable App with the vision that the newest versions of iPhone and Android devices will have the necessary GPS accuracy to locate fruit trees within decimeters of accuracy.
GPS in newer smartphones works well enough and the newest smartphones have a great accuracy already.
For older devices, we recommend that users of the Farmable App use an external GPS system to ensure the necessary accuracy of the GPS data being used to track job performance. You may already have a built-in GPS unit on the equipment that you use on your farm, and we will look into connecting with this in the near future.