Inbox takes the approach that - by organizing your emails intuitively - the clutter is kept in the background. The backdrop to this, of course, is that we're getting more emails than ever. We're contributing to that every day by doing things like emailing ourselves reminders and asking for newsletters we never read. Inbox can't solve that, but it can make things more manageable.
Inbox takes its cues from a multitude of third-party apps including Dropbox's Mailbox and Boomerang as well as some nifty Google Now integration. There's plenty to see here and, while it's tempting to call it a beta, it really isn't and Google says as much in the limited documentation it supplied to us.
The standard Google design language is used, and it works extremely fluidly on the web at inbox.google.com just as it does in the Android (Jelly Bean or later) and iOS 7+ apps. Google says Inbox was built with the phone in mind, but we found it great to use in the browser, too (it only works in Chrome for now). Other browsers and tablets will be supported in due course.
All you need is that invite. Don't have one? Email firstname.lastname@example.org, though there's no telling how long you might have to wait.
Google says its new app is designed to complement Gmail, not replace it (at least, not for the time being). By its nature, it's more at home with personal email, but there's no reason why the same principles couldn't be used for Google Apps accounts in future. Love using folders (sorry, labels) in Gmail? Well you can still add your emails to those same labels/folders.
Any changes you reflect in Gmail are also reflected in Inbox and vice versa. The only annoyance we found with this is that it doesn't use the Star/Starred system of pushing emails to the top of your inbox. This functionality is replaced with Reminders (see below). This works really rather well (also integrating with Google Now reminders)
Any attachments such as images and documents are now shown in the flow of emails in your Inbox - so you can see images that are attached to emails without going into the email itself.
This feature is called Highlights and it will also show you other Google Now-style information such as your flight status and any key phone numbers so you can tap and call. Naturally, you can also swipe across emails to remove them from your Inbox.
The killer feature of Inbox is the "smart bundling" of emails. We've seen a bit of this before with Google's Gmail Inbox Categories, but now that same technology flows through all your Inbox. So all your order confirmations will be in one bundle, and all your bills will be in the Finance bundle. It's for stuff you need to see, but don't want to be bombarded with.
Our favorite thing about this was the bundling of Social emails together. Begone annoying Facebook updates that we should have unsubscribed from!
You can add your own reminders to the top of your inbox, where they're pinned. This works with Google Now, so on Android especially you won't forget to pick up the parcel or reply to a key email. Just click the pin next to any email to set a reminder.
Equally, you can snooze an email until you want to deal with it. We love this and could really do with it on our corporate Google Apps account. Again, this integrates with the reminders.
At first look, Inbox is a lovely tool. We're going to try it out for our personal email over the next week to see what it's like to use on a regular basis. If only we could have the snooze and reminder features for our corporate Gmail, too.
Dan Grabham is editor of Lifehacker UK
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Dan (Twitter, Google+) is TechRadar's Former Deputy Editor and is now in charge at our sister site T3.com. Covering all things computing, internet and mobile he's a seasoned regular at major tech shows such as CES, IFA and Mobile World Congress. Dan has also been a tech expert for many outlets including BBC Radio 4, 5Live and the World Service, The Sun and ITV News.