Your fields, seasons, calculations and accounts are stored on the phone. They leave it only when you share a list, a PDF or a file yourself, or make a backup. Every calculation works without a signal.
The network carries map tiles (Esri satellite imagery, OpenStreetMap, OpenTopoMap for the topographic map), the date of the imagery and its earlier years (asked for an area rounded to about a kilometer, never your exact position), and Google's ads, consent form and ad-free purchase. Suggest an improvement sends the message you write, only when you send it. Your position is never sent.
The full text is the privacy policy.