[eBombzor]

Yes if you look at the basic concept it is filters and labels on steroids. However there were some key differences which really made a world of a difference (to me). As previously mentioned, the bundle was inline and was basically a larger message entity. It jumped to the top of your inbox when you received a new message (or you could pin it, another feature that isn't available in gmail sigh). The bundle included a preview for all attachments in chronological order (left -> right) which made it extremely easy to find the latest attachments. In addition, Inbox provided some default bundles that worked well and were actually very useful (trips, purchases, finance), not to mention the additional info boxes that summarized the information for these basic emails like flights, receipts, and package delivery.

Really though if you've never used Inbox it's hard to explain why people loved it so much. IMO it was the email client of the future. There were just these small details that Inbox provided that made the email experience so much easier and organized. My heart is broken knowing that I won't be able to use it anymore.