Ruler (Privacy Friendly)

(SECUSO) On the fly measurements with your Smartphone as ruler or protractor.GPL-3.0-only

Bubble

Spirit level and rulerGPL-3.0-or-later

GuessIron

Measure things with your cell phoneApache-2.0

Nonius

Ten measuring instruments. No ads, no trackers, no network.GPL-3.0-or-later

OsmAnd~

Global Mobile Map Viewing & Navigation for Offline and Online OSM MapsGPL-3.0-only