User blog comment:Keplers/G+ Hangouts Every Week?/@comment-4052371-20130606143622/@comment-4964341-20130607195020

@Gal: There is a sidebar where you can type on the desktop version. On the mobile (at least iOS) version, you can switch between the two.

There is an option to turn off both your microphone and your camera, so don't worry about being seen or heard, just. ..

Seeing and hearing. :P