Having a bot living in your chat is the arguably the single greatest way to improve, strengthen and polish your stream. Bots grant you the ability to leverage custom commands, give your moderators more tools to do their jobs and can enhance the overall fun via raffles and giveaways.
When it comes to bots, there are plenty to choose from, depending on your needs. Some even have their own web interfaces for customization and provide overlays for your video. A great place to research a bot is the Developer Showcase on our forums. Be sure to ask around on social networks as well. A lot of bot developers are active and willing to answer any questions you may have.