Last week, Microsoft released the latest update of Windows 10 for phones, build 10051, which brings in new features and UI enhancements. Unlike the first Windows 10 for phone preview, which only worked with low-end budget Lumia's, this new build works with all Lumia handsets, except for the Lumia 930 and Lumia Icon. Here's a look at some new features coming to the final version when it's released later this year.
Project Spartan
Microsoft's new web browser that will work across all Windows 10 devices, is available in this tech preview build for Windows Phone. We took a look at Project Spartan on Windows 10 for PC earlier this month, and the mobile version's design is quite similar, but it's currently lacking some the PC version's features. Namely, the ability to write, draw, or type directly on a web page, which Microsoft calls Web Notes. One feature in this build Spartan does share, though, is Reading view, which provides an uncluttered web page that only displays the text and images in an article.
Calendar and Mail apps
These apps are part of Microsoft's universal apps that will run on Windows 10 across all platforms. They have a fresh new interface, and you can easily toggle between email and your calendar without having to return to the Start screen. The email app also provides some powerful Word-like formatting features that allows you to do simple document style formatting, or complex tasks like creating tables all within the app. Both apps are compatible with Exchange, Outlook.com, Gmail, Google Calendar, Yahoo, Office 365, and other online accounts.
Maps
A preview of the the new universal apps that include aerial imagery, local search data, and voice-guided navigation, Maps brings Bing maps and Nokia's HERE maps together in a single app.
People app
The People app is also a new universal app with a revamped design that's intended to be the comprehensive list of all your contacts. It includes contacts across services like Gmail, Facebook, Exchange, Outlook.com, etc. and promises to allow easier management of contacts and the ability to connect with them quickly.
Other items of interest
New Phone and Messaging apps: Both apps have received a new visual design, and the Messaging app has a new feature that lets you switch from a text conversation to a voice call with the tap of the phone icon button.
App Switcher: The app switcher has been updated and supports landscape view. Also, on larger displays, (like the Lumia 1520), it provides a grid layout of recent apps. To use the App switcher, tap and hold the back button on your phone to access up to 15 recently used apps.
No Office: The Office hub is gone in this build, and will be replaced with the new upcoming Office universal apps. Because of this, you can't open Word, Excel, PowerPoint, or OneNote files in this preview.
Send Microsoft feedback: Microsoft does want your feedback on Windows 10 for phones, and you can give it by launching the Windows Feedback app. Alternatively, any time you want to provide feedback regardless of what screen you're on, press the Power+Volume down buttons on the phone, and the feedback app will open up directly.
Summing up
Installing this build isn't for the faint of heart, and should be reserved for Windows Insiders who have an extra phone to put these test builds on. Just like with Windows 10 preview for PC, it's not advisable to preview builds on your main Windows Phone either.
I've found this particular build to be the most buggy yet. Most new apps seem half done, they are unstable and crash, and there are several known issues, which you can find out more about on Microsoft's blog. Still, if you're an enthusiast, this lets you try out new features, and see where the mobile version of Windows 10 is heading.