Plan the first app release around one user problem, separating essential functionality, acceptance criteria and later improvements.
An MVP is not an arbitrarily incomplete app. It should solve one core need in a usable way and support decisions about the next release. Login screens and empty menus do not accomplish that.
Choose one core journey
Define the starting point and completed outcome. Finding a slot, booking it and receiving confirmation form one appointment journey. A missing middle step can make the release unusable.
Separate essential and later work
Task completion, error handling and necessary security belong in the essential scope. Advanced personalisation may wait. Prioritise the user outcome rather than development convenience alone.
Write testable acceptance criteria
Specify that a slot cannot be double-booked, cancellation updates availability and failed actions show useful feedback. Give design and development the same definition of completion.
Plan learning after launch
Decide how to collect feedback and observe task difficulties. Keep new ideas in a separate backlog after scope approval instead of continually expanding the delivery target.