Do you think it's confusing? The http://appointmentreminder.co domain is just for the landing pages. Users login and use the webapp under the https://reminderbookhq.com domain. I'm hoping this helps with SEO and clarity when someone lands on the http://appointmentreminder.co domain. I know there is some debate about whether a non-(.com, .net, or .org) is weighted for SERP ranking.