Your lines, plans, prices, customers, suppliers and photos are stored on the phone. They leave it only when you share a PDF or a file yourself, or make a backup. Android backup moves them to a new phone.
The network carries map tiles (Esri's map, satellite and hybrid views, OpenStreetMap as a fallback, OpenTopoMap for terrain), the date of a satellite photo and its earlier years (asked for an area rounded to about a kilometer, never your exact position), the address you search (sent to Nominatim, OpenStreetMap), 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.