If you want to add your logo to a slide at the front or end of your presentation, be sure to learn about the logo slide-type available to all Haiku Deck users. More on that here.
Haiku Deck Pro subscribers can also replace the Haiku Deck logo with their own on the web playback page, on the final slide of iOS presentations, and on pdf printouts. Look for this behind the shield icon in the Haiku Deck editor.
This 20 second video shows how it works: