Bunpro is so fresh you could eat it like sushi. I think it came about on November of last year.
One big tip for new users is, it works kinda like WK but if you mess up, you actually have a chance to erase your answer and input another one. This is good for trading colloquial versions of answers for formal ones and vice-versa, but it looks like it only actually tracks your answer in the SRS system after you go to the next item in the review queue. So if you mess up an item, erase your answer while still in the same item, then input a correct answer, that item will count as “correct” and will add to your streak even though you messed up at first. Not sure if that makes any sense but if you want the system to work as intended, go to the next item with the wrong answer if you mess it up, don’t erase it and re-do it.
When the item comes back again in the same review session, you’re free to do whatever you want as it will already count as wrong for that session.
Edit: Also, in the lessons, you’ll get a chance to read a few sources explaining that grammar term. I thought you had to tick the checkboxes to add the item to your review queue or some example sentences related to it, but as it turns out, the checkboxes are a personal “Okay, I’ve read this source, I can keep track of that here.” thing. It’s up to you to be a good boy and read the sources explaining the grammar item you’re about to add to your review queue, but it has no actual bearing on anything on-site and you can just add the items to your review queue without ticking any of the boxes.
Edited for clarification.