By invitation
Join the Beta.
Daybook works in full today. It is in Beta while it is readied for the App Store and Google Play, which means a few things may still change, and that Mark reads every message himself.
The Beta is by invitation. Whoever told you about Daybook, a nurse, a clinic, a friend or a message from Mark, gives you a short code. Type it here and the next steps appear.
No code, or lost it? Email support@mymedicaldaybook.co.uk and say who told you about Daybook. Already in someone's circle? Ask them for an invite link instead; it joins you to their circle, no code needed.