I’ve just re-discovered kaijugation and am currently obsessed with it. I tried it a while back and didn’t quite get it, so I used it maybe once and then completely forgot about it. But the other day I stumbled across it again and spent some time figuring it out a bit more, and now I can’t stop using it. I’m hooked, it’s all I think about atm 
It’s been really fun to be able to take a conjugation I know I could improve on, practice it at the most basic level, and gradually introduce more complexity to the reviews. I can see the way I’m improving, and it’s doing wonders for my motivation. It’s also fun to be able to target a conjugation I’m a bit wobbly with and isolate it for practice, and I find with this it doesn’t take me long before I feel like I’m starting to get it.
But now I’m wondering what else I’ve missed out on 
So, what’s a Japanese learning resource that you tried using previously that didn’t do anything for you for whatever reason at the time, but that you’ve since tried again and now love?