Since its launch on June 28, Google+ has been an invite-only social network, where the only way to create a user account was to receive an invitation from a current user. For months, people waited as invites slowly trickled out, but on Tuesday Google announced it will open up the platform to everyone.

For the past 12 weeks we've been in a field trial, and during that time we've listened and learned a great deal. We're nowhere near done, but with the improvements we've made so far we're ready to move from field trial to beta, and introduce our 100th feature: open signups, wrote Vic Gundotra, Google's senior VP of engineering and Google+ project leader, on Google's blog.

Gundotra also announced eight other new features, most of them improvements to Google+'s group video chat platform Hangouts. Now, you can join Hangouts on your phone, as long as you own an Android 2.3+ device with a front-facing camera (iOS support is coming soon), and now Hangouts supports screensharing, a sketchpad, and Google Docs, for when you want to write or plan something as a group.

Besides Hangouts, Google+ also added a much-needed tool to the overall platform: Search. Now, when you type what you're looking for in a Google+ search box, Google+ will return relevant people and posts, as well as popular content from around the Web, according to Gundotra.

Google+ got off to a hot start in July, amassing 20 million visitors in its first month, with its users sharing more than 1 billion pieces of content daily. Users praised Google+ for its clean interface, the ability to share different content with different friends, and the platform's potential for integrating other Google products, such as Documents, Calendar, and Reader.

Since August, however, interest in Google+ has waned considerably. With Facebook ready to make several big announcements about its site at the f8 conference Thursday, Gundotra chose a good time to release Google+ to the public and fan the flames a little more.

Insiders also expect Google to release two new features to its social network, including Google+ Games, which has reportedly been in development since the company invested more than $100 million in social gaming start-up Zynga, and Google+ Questions, where users can poll their friends.

At the moment, Google+ has a little more than 25 million users, mostly based in the U.S. and India, compared to Facebook's 750 million active users across the globe.