"USB Web debugging" is one option
"printing it on the screen" another.
But I prefer remote debugging through 'adobe edge inspect' formally known as adobe shadow. It uses weinre internally (=WEb INspect REmote)
You just install it + a small plugin in the browser (Chrome) and a free app you can download in the play-store. Then you have all the tools like the Chrome Development tools.
It has also support for iOS and Kindle Fire
Update
Like Chris noticed, you have to pay a subscription to use edge inspect. A cheap alternative is to use weinre directly, it's the base of edge inspect. Here's an article about how to set it up.