In fact, as you go through the flashcards, BunPro will recommend websites where you can learn more about the grammatical feature or word in question, as well as the page number you should go to in certain textbooks. And as well as opting for the standard course order that seems to correspond with the JLPT, you can choose to study the flashcards in pathways that correspond with Genki, Minna no Nihongo, Tae Kim, and more.
You can dip in and out of the pathways as you wish, and add and remove content from your flashcard reviews. Each level is divided into sublevels and themes, which makes it easy to spot material you don’t yet know. There are also community discussions about the different grammar points.
You could skip the textbooks and just study with BunPro, although it would be a much more superficial introduction to Japanese. What’s more, you would need additional resources for the kana, kanji, vocabulary, and reading, writing, listening and speaking practice.
The clue’s in the name, after all: BunPro wants to help you become a pro at Japanese bunpō or grammar. It doesn’t do much else, but as a supplementary grammar resource, it’s a great tool.