Something similar to the Kana Practice, but for conjugating, such as te form and other conjugations that are used often just to help drill it into your brain.
While, I’m at it I also think something to practice recognition of godan and ichidan verbs would be good. You could be shown a verb and you say whether or not it is godan or ichidan, this could also apply to transative and intransative, although some verbs are transitive and intransitive at the same time.
Just thought something like this would be useful to help really drill things like conjugations and how to recognize Godan, Ichidan, Transitive, and or Intransitive Verbs.