In need of a grammar practice resource

Hey, all. I've been casually studying Japanese for a bit now, but this year I really committed myself to tripling down and taking it more seriously. I use a variety of resources, but my primary method for learning grammar has been Genki.

I've recently finished Genki I, and I think I need to spend more time (a couple months give or take) reinforcing the grammar points I learned in I before moving onto Genki II. I already did all the exercises in the text and workbook and I would like something more than just reading.

Does anyone know if there is a structured resource that can give me repeated exercises and structure to learn grammar? My experience with apps like Duolingo is that it's a terrible method to learn grammar but I don't know if that's the case for something like Bunpro or Renshuu.

by invisible_face_