I have set this as the New Tab page on my Android tablet, and it is exceptionally good with a wealth of settings for further customisation. I use groups in the same way that I use folders on the bookmarks toolbar of my Windows Desktop.

The only small point - which has been mentioned by another user, is that it could be even better if it were possible to rearrange the thumbnails within groups, but the developer's response suggests that this may not be possible. However, it is nonetheless still a superb extension.