...
Change Record Owner from GoMeddo to another user for all objects which need to be accessed by the Guest user for (this list will be longer if you use more GoMeddo functionality)
Calendar
Dimension
Reservation Type
Reservation
Reservation color
Resource Type
Resource
View
...
Go to Setup
Go to Sharing Settings
Define a criteria based sharing rule for at least the following objects (this list will be longer if you use more GoMeddo functionality)
Availablility
Calendar
Dimension
Reservation Type
Reservation
Reservation color
Resource Type
Resource
View
...