Idea: it would be more interesting/competitive if you could immediately see others' submissions, and if those words were then "taken" and can't be reused.

Currently you're just kind of twiddling your thumbs after you submit and run out of ideas.

It was also not immediately obvious to me that you can submit multiple words, so I was wasting time entering and deleting attempts before finally submitting the best one.

Finally, instead of fixed timers between rounds, you might want to have a "Ready!" or "Go!" button.