Draw and label
Pick a tool and draw on the map. Each drawing becomes its own layer, so you can give it a name and colour.
Using your phone's GPS
Keep the app open while recording: the screen stays on, and phones stop sharing location when it's locked or in the background.
Your location is only available when Merra-map-lite is opened from its web address (https), for example https://map.merra.org, not from a file.
Tip: click a layer's name in the list below to rename it, change its colour or reshape it.