There's been a fairly steady stream of Windows Phone 8.1 leaks over the past couple of months that've given us an idea of all of the new goodies that Microsoft is packing into the platform's next major update, including an "Action Center" notification panel and the ability to set a default messaging app. Today the leaks continue with some details on WP8.1's Start screen customizations and the new version of Internet Explorer.

According to a leak from LiveSino, Microsoft is planning to allow Windows Phone 8.1 users to set a custom background image that'll be shown behind the Live Tiles on their device's Start screen. The site has shared an image from the WP8.1 SDK that shows an option to "Change your phone's background" as well as an one for a "Start background." 

Also included in this leak is an option to "Show more tiles," which The Verge says will enable users to use a three-column Live Tile layout on their Start screen. That option is currently available to larger-screened phones like the Lumia 1520, but it's said that the feature will be extended to devices like the Lumia 920 and 1020 in Windows Phone 8.1. Another Live Tile-related feature that Microsoft is said to be testing is the ability to skin Live Tiles with an image or even make them transparent.

Internet Explorer 11 is also expected to receive some major new features with the jump to Windows Phone 8.1. Perhaps the most notable addition is tab syncing, which will let Windows 8.1 users open up their recently-viewed tabs on their Windows Phone 8.1 hardware. Some of the other add-ons said to be coming to IE 11 include Reading View, private browsing, a password manager and the ability to upload and download content.

With all of the features included in today's leak as well as the Action Center and Cortana personal assistant, Windows Phone 8.1 is shaping up to be the biggest update to Microsoft's mobile platform to date. While additions like the oft-requested Action Center are sure to garner a lot of attention, the customization features outlined in today's leak will be big for Windows Phone as well. Users can currently resize their Live Tiles and select an accent color to change their hue, but having the options to set a Start screen background image and skin the Live Tiles will raise Windows Phone's customization level significantly, and I'm betting that many users will appreciate being able to make their phone even more personal.

Of all the Windows Phone 8.1 features that've leaked so far, which one are you most excited for?

UPDATE: Developer Jeremy Sinclair has posted a large list of new features included with the Windows Phone 8.1 SDK to his blog. There are quite a few notable additions, including an option to update apps automatically, double-tap to unlock, double-tap to power off, ability to change the default SMS app and Quiet Hours, which is a sort of "Do Not Disturb" mode that will prevent notifications from appearing for a set period of time. The full list of features shared by Sinclair is as follows:

• Sharing secure WI-Fi Networks with contacts if they have Wi-Fi Sense. They don’t get to see the shared password though
• Social notifications will now show up in action center by swiping from the top of the screen
• Operators can now control data sense limits remotely
• Operators can also install certain applications once a SIM card is detected
• Along with normal updates, there are now “important” updates.
• Options to always download emails and pictures within them
• Encrypted and signed e-mail support
• Change default SMS app. You can also change which SMS app will show notifications.
• Enterprise enrolled phones can have their passwords changed and remotely locked
• “Type as I swipe through letters”. This means we will be seeing Swype-like functionality.
• Geofence monitoring support. Geofence is a boundary around a place of interest to you. Location services can monitor geofences to tell your apps when you’re entering and leaving them. This would be really good for IFTTT
• Office Lens support: “Download the Office Lens which scans whiteboards and documents directly in the camera as a Windows Phone Lens.The Office Lens lets you scan whiteboards, documents, and more with your phone’s camera, then optimizes the images so they’re clear and easy to read in your notes.”
• The phone will have to update to the latest version before you can restore it to factory settings
• Option to update store apps automatically
• Option to update store apps when only on Wi-Fi
• App Suggestions by location
• Manual App Update checks
• Video Calling Support? I don’t know if we will be given choices of which VOIP provider to use. Maybe Skype video calling will be built-in?
• Password protected Office document support
• Trusted app list for NFC that will remove the need for asking whether you want to open a particular app.
• In-call speech commands. You’ll be able to say “Call XXXXXX”.
• Double-Tap to unlock your phone
• Lock Notification
• Quiet Hours
• Double Tap to Power Off
• Notification if charger isn’t of adequate power
• Screenshot button combination is now Power + Volume Up (Since the newer phones will have the start button on screen)
• Chkdsk for SD Cards essentially
• Apps on SD Cards are only allowed from ONE originating phone. If it detects that apps from another phone are installed on the SD Card, then it will ask to delete those first
• Voice Narrator for Accessibility
• The Search button will be the new way to open Speech instead of the Start button
• New Email sync options with accordance to usage patterns (i.e. If you get a lot of mail on particular days and if you don’t check mail every day).
• Change the size and amount of tiles on your start screen.
• Wallet supports tickets and membership cards
• App Syncing
• Backups now include application data
• Screen Reader functionality
• Screen Recording functionality
• Inner Circle of contacts. Up to 40 contacts can be in the inner circle.
• You can favorite photos by tapping a heart icon
• Virtual SmartCard support

Via The Verge, LiveSino, WPCentral, Sinclairinat0r