Coggle is not a Google app but it works with a Google Sign in. You can create simple mindmaps and share them with others. I can see students using this as a quick easy way of getting all their thoughts down, save as a PDF or a graphic and then uploading to Evernote, Google Docs or any other application. You cannot use it on an iPad in Safari but you can on the Chrome App. The Puffin app (Free or NZ$4.19 for iPad) will also allow you to add content on the iPad.