Launch URL takes the form:
curious-edinburgh://DOMAIN?tour=TOUR_NAME&protocol=PROTOCOL_TYPE
i.e.
curious-edinburgh://curiousedinburgh.org?tour=Science&protocol=insecure
The protocol query string item is optional and can be either secure or
insecure. However, any value other than secure results in the API endpoint
url being prefixed with http://. If protocol is specified assecure then
the API endpoint url is prefixed with https://.