This resource is specifically for language teachers! There are some free resources available, but the best features are paid for.
The price is $45 per school + $5 per teacher. I emailed the host and he cut me a deal for $30 since I am paying out of pocket.
Students can either make their own accounts if you want to keep track of their progress, or you can create a dummy student account that all students use to log in (I do this and do not track progress and only use the site as practice).
You can create either grammar or vocabulary activities. The grammar ones have one format, but the vocabulary lists have a timed quiz option, games, and more.