In “⚙️ Settings” → “Area / Length Units”, choose the main unit, an optional second unit and the length unit: m², hectare (ha), acre (ac), ft², pyeong / m, km, ft, yd, mi. Changes apply to the map immediately.
The app supports English, Español, Português and 한국어. It starts in your phone's language; change it under “🌐 Language” in “⚙️ Settings”.
“🎛️ Display” on the left of the measure screen turns these on and off: