A common misconception is that these tools would work on production APIs. They won't. They are only useful for local development since in production all data is almost certainly encrypted with SSL and no man in the middle technique like this proxy would work.

It's unfortunate that these tools don't explicitly rule that out as not to confuse users.

To actually reverse-engineer production APIs you'll either

a) need access to either the client or the server source code so you can deploy a custom certificate for SSL

b) create your own certificate authority and gain enough trust to have it be accepted on major OS' (this option requires you to be NSA or a secret govt affiliated agency)