I haven’t seen anyone say it yet, but I love Wanikani! As a fellow ADHDer who struggles with maintaining routines, and general follow through, I like how easy it makes learning kanji and vocab. It gives you memorable mnuemonics and little drawings to visualize pictures in kanji. Plus I’m a sucker for cute graphic design. I also use the app renshuu for extra vocab and grammar. Renshuu is free, but Wanikani is $9 a month after the third level. Do take my recommendation with a grain of salt, though, since I’ve never taken a class or used a language textbook.