I remember spending a weekend once in graduate school making a bilingual crossword puzzle. It took time, and it was a fun. But was that time really worth it? Maybe not, in hindsight.
If I’d had this, I probably would’ve used it: Crossword Labs.
Here’s their example:
Type in the clues and answers, hit “generate” and you’ve got a crossword puzzle. The password you use to create it will give you access to the answer key.
There are lots of ways to use crosswords for language study. Create a puzzle around a theme. Like this one, about a movie called “If I Stay” (Japanese title: イフ・アイ・ステイ 愛が還る場所) I didn’t create this one, so I don’t have the answer key.
Other ideas? You could try creating your own game app or software! This crossword puzzle maker was created by a university student at Washington State University.