Donum is a GPS land area measuring app for Android. Measure a field or plot in four ways: Area (tap corners on the map or enter them as coordinates), Distance (draw a line), Point (mark one location) and Walk (walk the boundary with the screen on while GPS fixes are recorded). The app shows area, perimeter and edge lengths in m², hectare, dönüm, km², acre, square foot, square yard and square mile. Plots can be saved with a name, note, colour and group, and exported as GeoJSON, KML, GPX, CSV, a PDF report or a plot card image. Maps use OpenStreetMap tiles (standard, OpenTopoMap and a high-contrast layer). Area is computed on the device; no measurement or calculation is sent anywhere. Area, Distance and Point modes, entering corners by coordinates, 5 saved plots, CSV export and the backup file are free. Donum PRO is an optional auto-renewing subscription sold through Google Play Billing; plans, prices and any offer are shown on the purchase screen before you confirm. There are no accounts, no ads and no analytics. Location is read only while the app is open. Donum is not a cadastral survey.