To start with: This thread is where you can find all the stuff you need
/t/List-of-API-and-Third-Party-Apps/5495/1
Personally i mostly only use convenience stuff.
Real Numbers and Real Times show you the real number of reviews and the real times (not just “42+” or “about 2 hours” but “77” and “2 hours 7 minutes”)
Then i also use Wanikani Improve, for it’s auto forwarding feature because i started to always hit return twice after answering when i was sure i was right to get to the next item quickly. Unfortunately i wasn’t always right, and this way you will skip the opportunity to see what the correct answer would have been. But while the script tells you whether you were slightly off or if there were alternative answers and you can recheck the info from the previous item, the info displayed then is not always what you want. This is due to the fact that the script isn’t really updated anymore.
I also use the part of speech script, but now that this is a built in feature for WK (it was just integrated a few days ago), it probably isn’t necessary anymore for you. It still is for me because for now the data is only present for low levels, but that shouldn’t be a problem for you.
I’m sure people will suggest the lesson and review reordering scripts, as well as the ignore button. While these scripts certainly have their merits, they are two edged blades if not used with perfect discipline.
The reordering scripts allow you to level quickly by doing the lessons and reviews for the leveling relevant items first (radicals, then kanji, then vocab) if you don’t have time to do all the lessons/reviews at once. Especially the lesson reordering is useful in this regard, because you can do the relevant lessons first and then the vocab lessons in the next few days. But the danger is (and there have been people falling into this trap) that you only do the lessons and reviews for radicals and kanji, and not for the vocab. This will lead to huge lesson/review stacks, which is discouraging to tackle them. And you will also miss out on learning the other readings, as well as better cementing the reading and meaning of kanji into your head. And you will of course miss out the most important part: vocabulary. With just kanji you can’t read anything, in the end you NEED the vocabulary.
The ignore button allows you to say “yeah, the answer i entered is wrong, but it was just a typo, honestly!”. If you really really made a typo this is fine, but if the button sits there to fix your mistake which will hold you back from leveling another 2 days, it becomes really tempting. Or to fix “yeah, i was almost right, that’s good enough”, while it isn’t. This button can be a boon if used with care and discipline, but it can be a curse if not.