Other

CoastSnap (citizen science project for coastal change)  https://www.coastsnap.com/

GreenZones (environmental badge): https://www.green-zones.eu/en/  

Maps.me (map service): https://play.google.com/store/apps/details?id=com.mapswithme.maps.pro&hl=en&gl=US

IceWatchers (archaeological glacier finds):  https://play.google.com/store/apps/details?id=ch.biolovision.glarcheo&hl=en&gl=CH