Credits
Assets must be CC0/public domain, MIT, Apache-2.0, SIL OFL (fonts) or CC BY 4.0 with credit. No non-commercial, no-derivatives or personal-use-only licenses. See SPEC.md §4.16.
Fonts
Baloo 2by Ek Type · SIL Open Font License 1.1https://fonts.google.com/specimen/Baloo+2
Nunitoby Vernon Adams, Cyreal, Jacques Le Bailly · SIL Open Font License 1.1https://fonts.google.com/specimen/Nunito
Art
NumNinja app iconby NumNinja project · Original work (project-owned)
App icon for iPhone and iPad home screens, 180 pxby NumNinja project · Original work (project-owned)
App icon for Android (maskable), 512 pxby NumNinja project · Original work (project-owned)
App icon, 512 pxby NumNinja project · Original work (project-owned)
App icon, 192 pxby NumNinja project · Original work (project-owned)
Pets, belts, ring and rank shields (drawn in code)by NumNinja project · Original work (project-owned)
GeoNinja world map (land, continents and some countries)by Made with Natural Earth (naturalearthdata.com), via the world-atlas package by Mike Bostock · Public domain (Natural Earth); world-atlas packaging ISChttps://www.naturalearthdata.com
Pictures and sounds
Picture-password picturesShown with the device's own emoji font; no image files are shipped.
Sound effectsGenerated in the browser with the Web Audio API; no audio files are shipped.
GeoNinja map picturesGrid maps, compass roses, key symbols and contour lines are drawn in code; the places on them are emoji from the device's own font.