Yesterday several developers got invited to check out an early Windows Phone 8.1 SDK. This allows devs to start working on apps before Windows Phone 8.1 is released. It also allows devs to share information about the new OS update on Reddit. One developer has done just that. Several new features have been shown off that should make users happy. Let’s take a look.

Change default Messaging app

In a previous OS update Microsoft added the ability to choose what camera app you would like to launch with the camera button. In Windows Phone 8.1 Microsoft is adding this ability to Messaging as well. Developers will be able to build apps to replace the default Messaging app. We could see apps like WhatsApp incorporate this into their app.

Universal App Support

The first signs of merging Windows Phone and Windows RT are present in WP 8.1. The SDk includes something called “Universal App” support. These are apps that can run on Windows Phone and RT. They share the same HTML and JavaScript code. We’re not sure how hard it is to code for both, but this is cool.

Battery Power Sense

This feature is pretty easy to describe. Think DataSense for battery life. The app will track your battery usage and show which apps are using up the most power. Couple this with the existing Battery Saver mode and Windows Phone will be great at squeezing out every ounce of battery life.

Multitasking

Developers are reporting that the back button no longer kills an app. Instead apps are suspended in the background like in Windows 8. You can also swipe down on an app from the multitasking screen to kill it.

New camera UI

The camera app has recieved a UI update in Windows Phone 8.1. There is a new top bar with shortcuts to lenses, flash, rear/front camera, and the gallery. The buttons across the bottom switch between photo, video, and a new burst mode.

YouTube

This one is very interesting. Developers are reporting that the YouTube mobile site operates differently in Windows Phone 8.1 Internet Explorer. Instead of videos playing in a full screen mode they just play in the embedded area.

Microsoft has left a few of the big consumer-facing features out of the SDK. Devs have reported that the search button and Bing-related behavior bring up errors, which clearly points to Cortana being stripped out. Microsoft is likely keeping these features very close to their chest. We’ll see more about them in April. What do you think about these new features?