Under iOS 9, I've used the accepted answer here: Transport Security has Blocked a cleartext HTTP
I added the entries to my Info.plist file under
App Transport Security has blocked a cleartext HTTP (http://) resource
load since it is insecure. Temporary exceptions can be configured via
your app's Info.plist file.
Using this link (http://timekl.com/blog/2015/08/21/shipping-an-app-with-app-transport-security/) from the comment above, I found that switching the environment variable
1 produces a detailed log of all the requests.
This allowed me to trace the requests coming from a webView where I'm loading my own domain, which in turn loads things like MixPanel and Google Analytics. Entering those domains into the Info.plist file fixes the issue, however, we're instead simply going to load the https versions of these libraries.