Guess what? You're done!!! Congratulations, you just "finished" your first rails app!
(They're never really ever finished... have fun tweaking it!)
You get another sticker! :)
If you got all the way through Suggestotron with some time to spare, here's some extra stuff you can try:
Add a downvote button that does the opposite of what the upvote button does
Create upvote and downvote methods in the Topic model and use those in the topics controller instead directly modifying the topics votes
Sort topics by their number of votes
Add an 'about' page, linked from the bottom of the Suggestotron topics list. Link back to the Topics list from the About page so users don't get stranded.
If your class has a lot of time left over:
Users should be allowed to vote only once: give votes a user_id and allow a user to have voted on each topic only once. But wait, what is a 'user' in our system? Get a volunteer to introduce everyone to Devise, a simple way to add authentication to a Rails application.
Users should be able to give a post a 'negative' vote instead of a positive one. How might you represent that in this system?