The gmail team at Google launched this new app called Inbox which I've been trying out for a few days now. It's a web app and also a mobile app (Android and iPhone, not sure about Windows).
It really is just another app to check your email but it is AWESOME. I actually already turned off my Gmail notifications because I don't plan on using it anymore. I also no longer use Keep for reminders because Inbox handles reminders and emails in a very intuitive way.
It's nothing revolutionary, Inbox is similar to Gmail but a little more task oriented. When you get an email it gets bundled up in a category, you open it and have a few options: Snooze it to reply or read later or mark it as Done or pin a Reminder to it. You can also just close it and it will stay in your inbox as a 'read' email if you're into that...
You can already do all these tasks with the current Gmail but Inbox really makes it easier and simple. Marking an item as Done is the same as Archiving on Gmail. It is not deleted but it is removed from your inbox. Before, I probably had thousands of emails in my inbox that were already read but I didn't bother Archiving them. But now thanks to Inbox, I got my inbox empty. If you're already very organized with your Gmail maybe Inbox will not be that big of a deal but for people like me who got lazy about it then it's perfect.
Currently Inbox by Gmail is invitation only. Post your emails in the comments and if I get more invitations I'll send you one.