Fill-in puzzles are a variation of the common crossword puzzle in which words, rather than clues, are given.

Features :
- Several levels of difficulty, from beginner to very hard
- A mix of crossword grid styles : american, french, italian, ... (the difference is in the way the black squares are placed)
- 2 new puzzles every day
- Several languages available
- Many settings to customize the features and the look and feel of the grid