Oh sorry, should have specified. You basically have to be on the same Wifi with both devices and then set your computer (get the IP in Charles via Help -> Local IP address) as the proxy in your devices:
https://www.charlesproxy.com/documentation/faqs/using-charles-from-an-iphone/
http://university.utest.com/how-to-set-up-charles-web-debugging-proxy-for-android-devices-and-mac/ (see steps in the bottom of the page)
Then you should be able to look if there are requests that correspond to what is logged.
And for SSL:
https://www.charlesproxy.com/documentation/faqs/ssl-connections-from-within-iphone-applications/ (bottom again)
http://stackoverflow.com/a/31288342/252627