Subsequently, at several different times over several days, a somewhat similar problem surfaced: I would close an application on the screen only to see it suddenly re-open. One more try at closing always finally closed it. I haven't seen any similar reports, so these could simply be a problem with the early-release review unit.
The 635 is technically the first Lumia device to get the newest Windows Phone 8.1 software, although the 8.1 preview version was used on the Lumia 520 on AT&T's network and got a few positive reviews, including from Computerworld's Ryan Faas back in May.
Windows Phone 8.1's biggest new feature is Cortana, a savvy voice-activated digital assistant.
Cortana is a very good digital assistant, but it's not quite as "truly personal" or artificially intelligent as Microsoft officials would have had us believe when it was first unveiled in April. In fact, Cortana is still technically in beta and it's not clear when the beta period will end.
Cortana will greet you each day with a text update and can take voice commands.
When Cortana is activated for the first time, you are asked a series of questions to help it establish your voice, behaviors and preferences. The first question I was asked was how I wanted Cortana to say my name. Then I was asked to state two things I do in the evenings and, later, my two main motivations for going out. (I tried to impress Cortana by saying I go out to learn something and to improve myself.)
After using Cortana for nearly a week, I couldn't detect much personalization from my answers to those initial baseline questions. Instead, I was given a "Good morning!" screen in text each day with the day's weather for my area and top headlines, followed by health, entertainment and business news. There didn't seem to be much, if any, automated customization of the content I was receiving. Perhaps I need to use it much longer to see the personalization benefits.
Cortana saves all your preferences in what is called a Notebook; you can tweak those preferences manually by tapping on the Notebook icon. For example, you can add sports to your interests and follow a favorite team (Red Sox, in my case, even though it's not a great year). I could then ask Cortana to notify me of score updates for the team.
For business users, Cortana can detect flight itineraries and other tracking information from your emails and add them to the Notebook to be able to provide reminders (with the user's permission, naturally). Users can also disable email integration entirely.
When I tested Cortana, some of the more basic requests worked really well, such as, "Show me the Mexican restaurants nearby" or "Show me the nearest hardware store" or "How far to the nearest airport?"
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