Drill
Twenty cards a set, four choices a card, scored in the page. The order is fixed per set so a class sees the same deck; the app's version learns what you miss and schedules it.
20 cards
Fossil taxa
Name the genus from the photograph. 191 photographed taxa in the pack.
20 cards
Minerals
Species from the IMA list, by sight. 120 photographed.
20 cards
Shell families
Families after WoRMS and MolluscaBase. 40 photographed.
20 cards
Formations and outcrops
The rock units by their look. 43 photographed.