Some unconventional aproach to learning grammar could be the one I do. I’m not sure if right away if you don’t have any background, but at least after the most basic of textbooks you should be ok to give it a try.
I do sentence mining using this method with Anki and some plugins.
I keep both the first 2 volumes of the Dicitonary of Japanese Grammar series and Handbook of Japanese Grammar Patterns at hand and resolve doubts as they appear in this terrific reference books.
Japanese the Manga Way serves as a great companion book for having actual samples with the use of those grammar points while explaning nuances in their use. I read it every week, it’s fun and a light reading, yet really clarifying in some aspects.
As far as grammar and learning it, I would limit all the SRS and nice apps to a minimum and just start reading (graded readers for japanese learners, basic japanese tales aimed at children, etc; and move forward as you see possible)
The SRS apps are great for memorizing… yet grammar it’s something your have to experience over and over to come through and get the actual uses for each grammar point.