What is the default port for the communication between mobile app server and devices?

Per default the http port 80 is used for the communication. It can be changed by using the config entry "httpPort" in the [mobileApp] section.
If you want to enable a secured communication, you have to use the https port which can be set by using the config entry "httpsPort".
Per default this entry is set to 0 which means that https is disabled. It must be pointed out that you need a SSL certificate for using https.
Please also note that http and https port must not be the same.