As you can see in the above image, two Lucid products are connected to my Google Drive account, Lucid Chart and Lucid Express. (More about Lucid Express shortly)
Functionality is somewhat crippled in the free version - you are limited to 60 items, but you can always break the flowchart into several sections if you need to.
Of course, Lucid Chart does far more than just flowcharts - as the next item shows.
Summary - Lucid Chart is well worth a look. And there is an iOS app for it too!
Now - just a couple of days ago an email arrived announcing LucidPress. It looks very cool, its in Beta at the moment, but I have had a quick look and this is certainly a tool that I'll try and use for an interactive newsletter in the next week or so. Check it out here.