Inbox by Gmail is now open to everyone, doing away with invites, and it also adds some neat new features such as the ability to unsend emails.

Google already has is popular Gmail, but last year it introduced a new email service called Inbox. At first Google Inbox launched as a beta, only to select users on an invite-only basis, and many Gmail users gave it a shot.

According to Alex Gawley, who leads the Inbox and Gmail teams at Google,  the company aims to make mobile email more powerful, reaching an efficient comparable to that of desktop email.

As previously mentioned, Google has added some neat new features to improve the experience, including the ability to unsend an email. If you ever sent an email to the wrong person, or hit send before proofreading or adding everything you wanted to communicate, now you can unsend it thanks to Inbox by Gmail.

"With Undo Send-now for the first time on your phone-you can take back an email right after sending in case you spotted a mistake, or have second thoughts," Google touted in a new company blog post.

At the same time, Google also added custom signatures to sent email. This feature may not be new or groundbreaking, but so far it has not been available in Inbox.

Inbox by Gmail aims to keep everything more organized, offers a cleaner look, and is easy to use. At Google I/O 2015, the company also announced that its Inbox service is ready to open its gates to all, ditching the invite system and allowing everyone to try it out.

"You've asked for invites. And we'd like to say yes to all of you, all at once. So as of today, Inbox is open to everyone-no invitation required. All your Gmail messages are ready and waiting. So if you haven't tried Inbox yet, download the app today, and start getting back to what matters."

"p.s. While we're still in the early stages of bringing Inbox to work, today we're also expanding the Inbox early adopter program so any Google Apps for Work customer who wants to join can do so."

Lastly, Google has plenty of reasons to celebrate - about 900 million of them - as that's how many users are now relying on Gmail. This is an important milestone for Google, getting Gmail closer to the one billion user count.

To learn more about the latest version of Inbox by Gmail, check out the videos below.