English 
French 
Indonesian 
Gaia GPS
Android: Phone, Tablet
iOS: iPhone, iPad
Type: Mapping, Citizen Science
Species: n/a
Wifi: Need to be connected to access map before going off-grid.
Search: n/a
Region: World
Languages: English
Price Range: Free version has been enough for our field work. In-app purchases for upgrades.
Recommendations:
What we liked:
The basic version working from free maps gives enough detail to do field work. Easy to mark pathways, boundaries, or monitoring points. Can record photos and notes with waypoints. Great for monitoring work in mangroves, seagrass, etc.
What could be better:
Requires a bit of practice using it before heading to the field.