The platform allows you to queue up tweets and post them at optimal times. When the most traffic happens and when the most tweets go out its the best time to tweet, which is sometimes counter-intuitive.
This tool works by both by monitoring the performance of your past tweets and tells you when most of your followers will be online. Original post
For more Twitter advices see
10 technical Twitter tips for journalists (JOURNALISM.CO.UK)
Top 5 tools to better times your tweets (MASHABLE)