Your Android phone is about to get an upgrade. Google today is making good on its promise to bring its Siri alternative known as Google Assistant to more Android devices, starting today. The company announced at Mobile World Congress over the weekend that its Assistant would soon launch in the U.S., followed by English-language launches in Australia, Canada and the U.K., as well as for German speakers in Germany.

However, Google didn’t commit to an exact time frame this rollout would begin, saying only that it would be sometime “this week.”

Today, Google Assistant is arriving, the company has now announced.

The new, A.I.-powered helper is something of an upgrade to Google Now, Google’s earlier proactive search and alerting service. The Assistant was first unveiled at last year’s Google I/O conference where it became a flagship feature on Google’s then-new Pixel smartphones.

Like Siri and Alexa, you can speak to Google Assistant using natural language. But it can also follow conversations where there is a lot of back-and-forth dialog, which makes it seems more human than some of the virtual assistants available today.

Google Assistant can also perform various tasks, like setting reminders, taking photos, assisting with translations, providing directions, checking the weather, operating smart home devices and more.

Third-party integrations called Actions – basically, Google’s version of Alexa’s Skills – will connect the Assistant to a larger app ecosystem. However, Actions have the advantage of not needing to be pre-enabled or pre-installed, as with Alexa’s Skills.

While initially a selling point for Pixel devices, it makes sense to bring the helper to more Android users, given Pixel’s much smaller market share and the heated competition between voice-based computing platforms.

With today’s launch, “hundreds of millions” of Android mobile devices will be able to take advantage of Google Assistant, the company said on Sunday.

But there are some limitations: Google Assistant works only on devices running unforked versions of Android 7.0 (Nougat) and Android 6.0 (Marshmallow).

That’s still a sizable chunk of the market, though. Marshmallow has a nearly 31 percent distribution share, while newer Nougat has more of a sliver (1.2%). Older devices running KitKat and Lollipop will miss out, but some of those may be upgradeable to a more recent version of Android.

To gain access to Google Assistant on a supported device, you’ll need to download the Google Play Services update from the Play Store when it arrives.

Once installed, you can launch the smart helper by pressing on the Home button, as you could with Google Now. You can also activate the Assistant by its hotword phrase, “OK Google.”