I’ve made a tool called sakubun - it helps you practice kanji and improve your vocabulary.
It’s customizable because it lets you make a list of all the kanji you’ve learnt so far, and it gives practice sentences that use exclusively those kanji. To make the kanji list, you can just import your WaniKani progress. You can also add kanji manually or import it from some other sources.
It has a collection of over 130K practice sentences with English translations, taken from the tatoeba project. The original tanaka corpus had more sentences, but sentences that were marked as unreliable are not included here.
The website works on all devices, and you can also install it as an app if you’d like - instructions for that are given in the website. Sakubun is completely free and open source software (GitHub, so feel free to contribute if you’d like!
Here are some screenshots:
Quiz on desktop, with light theme
Furigana on custom text, with dark theme
Any kind of feedback, suggestions, or criticism is highly appreciated