OneKontest

Twitter Contests
You can require users to be following one or more accounts before they can enter your promotion. You can also filter users with no profile image and less than 10 followers (usually fake accounts.)

Voting Contests
Have your users choose between 2 or more #hashtags, photos, videos, Twitter accounts.

Trivia Contests
Ask a trivia question and have the winner(s) picked from the people who answer it correctly.

Feedback Contests
Get feedback about a product or issue. Reward your users for their feedback.