Uuhhmm

1. Sign in
2. maximize learning,
3. ...,
4. profit.

Key	Description
`Shift` or `Control`	Peek on the back side of the card
`Spacebar`	Flip the card
`1`	Again
`2`	Hard
`3`	Good
`4`	Easy
`0`	Never show again
`Arrow key left` `Arrow key right`	Choose and activate previous/next tab.