on iOS I use an app called "CleverDeck"
I've even put sight-words and dolce-words in there for my youngest child to learn from (she's learning to read)
Another child has a copy of clever deck she used for finally solidifying her knowledge of the "times tables" she couldn't quite get clear in her mind. 78, 1112, and a few like that.
With clever deck you can quickly add your own cards.
A single fact may be best represented by more than 3 cards:
- word ↷ definition
- definition ↷ word
- example with word missing ↷ example with word filled in. (note: this is called cloze deletion)
- Basic strategy for 21
- Birthdays of people I know
- Children's (and pet's) names of friends
- Bash commands
- Ubuntu paths
- Guitar chords
- Guitar scales
- git commands
- interesting words
- words I commonly misspell
- Mental Models"
(See cheatsheets)