Our inboxes are all messed up. Information we need gets buried under the constant flow of emails, related emails get dispersed throughout our email clients, and actionable emails get lost among the reference once. Google's new Inbox app looks like it could greatly improve this experience.
The Android, iOS, and webapp--currently in invite-only beta--adds Boomerang-like features, where you can "snooze" an email to return to your inbox when you most need it (e.g., an email that tickets are going on sale the morning they go on sale, rather than weeks before). You can add your own reminders to emails, effectively turning them into to-dos.
Inbox will also intelligently supply information (called "assists") related to your reminders, such as the phone number or box office times for those concert tickets you're thinking of purchasing. It's a Google Now-like feature.
In addition, Inbox will group emails into "bundles" so related emails will be easier to find--useful, for example, when you have multiple reservations for a trip or several emails for a particular project.
The first round of invites for Inbox are going out today from Google (for press and friends of Googlers), but you can request an invitation at firstname.lastname@example.org. Don't worry if you get a bounceback message saying that address is getting too many emails at a time (of course it is)--you should get a reply from Google after that.
I'm looking forward to it. An email revolution couldn't come soon enough.