Blankout is an app specifically designed to exercise your ability to recall information anytime, anywhere. In the Options screen, choose whether you would like to iterate through the words in sequence, whether you want to ignore commonly used words or characters, or (with in-app purchase) customize which words or characters you want to ignore. Load, paste, or type your study material in the text box and tap the Start button to hide some or all of the words. Use the text field under it to guess the word (tap the Hint button for a clue) and tap the Check button to see if you were right! Lather, rinse and repeat. You now know everything*. Currently supports English only.
Optimal options for study material that requires relationships to be memorized (e.g., definitions or outline format):
-Disable "Highlight in Sequence" (disabled by default)
-Hide any amount of words you wish
Optimal options for memorizing a passage:
-Enable "Highlight in Sequence"
-Tap "Clear Words" and/or "Clear Characters"
-Hide all the words (drag the slider all the way to the right)
*Everything that was in the text box.