Chances are you can't run Google Now on your Android phone. That's because the search giant's intelligent assistant only works on the minority of devices that use the current "Jelly Bean" version of its mobile operating system.
But there's a new, easier way to access Google Now: on an iPhone.
A recent update to Google's iOS search app introduced the free service to hundreds of millions of iPhones and iPads, providing competition for Apple's voice-based assistant, Siri. I tried Google Now on both an iPhone 5 and a third-generation iPad and found it very useful, though not as convenient or powerful as its Android counterpart.
Using Google Now for either Apple or Android devices first requires you to clear a psychological hurdle: How willing are you to share your life with Google?
Now is based on Google's analysis of your browsing history, mail, calendar and other online activities to predict the information you'll need before you actually need it.
There are extensive privacy controls that let you prohibit Google from, say, extracting information from your Gmail account about packages you're expecting. But the more information you restrict, the less useful Now becomes.
To test the service, I decided to go all in, even moving entries from my Microsoft Outlook and Apple calendars to the Google version to give Now the fullest view of my life.
Accessing Now on an iOS device isn't as easy as in Android, where it's deeply integrated and can be summoned by a finger swipe. On the iPhone, by contrast, you first have to launch the Google search app. Google Now appears as a stack of cards on the bottom of the screen.
When I swiped the stack, the familiar sparse white page and multicolor logo gave way to a location-customized logo -- in my case featuring images of the Golden Gate Bridge and other San Francisco landmarks. Meanwhile, the cards expanded into individual windows, each presenting me with specific information that Now concluded I'd like to know.
Based on my calendar, for instance, Now knew I had a meeting coming up at Google headquarters in Silicon Valley -- so a card provided a map, directions and current traffic conditions.
Owing to my search history and location, it knew of my devotion to the San Francisco Giants, so it automatically displayed the previous night's score.
Other cards appeared and disappeared from the stack depending on where I was and what I was doing. In the coastal town of Half Moon Bay, where I hadn't been for months, a card suggested scenic photo spots, and at the Caltrain station in Palo Alto I got info about the next northbound train.
In an airport, it would have provided gate and departure- time for my flight; in a foreign country, translation and currency conversion.
Like Apple's Siri, you can use your voice to launch a search, though you can't tell it to create an alert or a reminder, or send an email -- a significant limitation. And Google Now only works with Google services. Had I entered my meeting using Apple's iCloud instead of Google Calendar, I wouldn't have gotten the driving-direction card.
I encountered other drawbacks and glitches as well. Asking for directions in the iPad version of Google Now launched the shrunken iPhone version of Google Maps, a much less pleasant experience than the Web-based version, or even Apple's mapping app.
When I stood in San Francisco's Embarcadero Center and asked each assistant to "find a Chipotle near me," Google's top choice was in Berkeley, 12 miles away. Siri pointed me to the one within two blocks.
Most maddening, while Google Now correctly deduced my home address, it flubbed my work location, targeting Bloomberg's Palo Alto office, where I usually work only one day a week, and resisting several efforts to override it with the correct San Francisco address.
On the other hand, I saw no evidence of an unusual power drain, a concern raised by some users. Google says the service uses cellphone towers and Wi-Fi hot spots to calculate where you are, rather than your device's more precise but power-hungry global positioning system.
Are the privacy implications of Google Now too creepy to justify using it? I don't think so -- but that's something you'll have to decide for yourself, depending on how much you trust Google.
As the saying goes, if you're not paying for a tech product, the real product is probably you.