Two weeks after the previous build (15014) we have a brand new Windows 10 Mobile version for all those on the 'fast' Insiders ring - highlights are the reading aloud of ebooks in Edge and the optional forcing of all audio to be mono in accessibility settings. Downsides are known issues with Microsoft Wallet and rotation in Edge.

From the Microsoft blog post:

Today we are releasing Windows 10 Insider Preview Build 15025 for Mobile to Windows Insiders in the Fast ring.

What’s new in Build 15025 for Mobile

Microsoft Edge can now read aloud: Microsoft Edge will now read aloud* your e-books just like on PC! Just press the “read aloud” button at the top-right corner after opening one of your e-books and listen to Microsoft Edge read you the book with focus on the line and the word being read along. This feature is also extended to all non-store EPUB files opened using Microsoft Edge.

*Supported languages: ar-EG, ca-ES, da-DK, de-DE, en-AU, en-CA, en-GB, en-IN, en-US, es-ES, es-MX, fi-FI, fr-CA, fr-FR, it-IT, ja-JP, nb-NO, nl-BE, nl-NL, pt-BR, pt-PT, sv-SE, tr-TR, zh-CN.

Microsoft Edge and emoji: Microsoft Edge will now display full-color, updated emoji by default on websites that use emoji.

Introducing Collections in Feedback Hub: A few months ago, we asked you what was one of your biggest pieces of feedback about the Feedback Hub. You said, “too many duplicate pieces of feedback!”. We love working with you to create a better experience for everyone using the Feedback Hub, so today we are so happy to announce Collections. Collections are now live in Feedback Hub starting with app version 1.1612.10251.0.

A Collection groups together feedback for similar problems and suggestions into single items that bring together all the voices who expressed that sentiment in one place. All of your individual voices will be amplified when your feedback and upvotes are joined together into collections, and you’ll be able to see just how big your voice can become. Same as with individual feedback, you’ll be able to upvote Collections, upload screenshots to show the engineering team a problem you’re seeing or a suggestion you have, and comment on the feedback with others.

Thank you for your feedback, Insiders. Because of you, the Feedback Hub is becoming better for ALL customers.

New mono audio option in Ease of Access settings: Visually impaired users use a screen reader application to read content on their phones and information to them, and frequently use headphones or earbuds to hear their device when in meetings or having conversations with others. When doing so, they generally use only one earbud to hear what’s being said from their device in one ear so the other ear is free to hear conversations and sounds around them. That can cause them to not hear sounds that may be directed to the other earbud. In order to change the sound to be mono mode and so all audio is directed to both ears, they used to need a physical earphone adapter. You can now switch your audio to mono straight from the new Audio section under Settings > Ease of Access > Other options.

The list of bug fixes is rather impressively long. But I guess we knew that Redstone 2 still had a load of glitches? Anyway, loads of them should now be sorted out, though see the 'known issues' below(!):

• We fixed an issue resulting in the Outlook Mail and Calendar tiles sometimes no longer updating for some Insiders until the tile had been resized.
• We fixed an issue where insiders with certain devices, such as the Lumia 635 and 636, might not have been able to manually change the brightness.
• Windows Insiders should no longer have trouble connecting to certain Google sites due to an implementation of a new security model being rolled out to further enhance user security.
• To help save characters when typing in fields with a character limit, we’ve added a new ellipsis child key for Latin-based languages (such as English, German, and French) when you press and hold the period key on the touch keyboard.
• We fixed an issue where the Quiet Hours quick action button in the Action Center wasn’t working in recent builds.
• We fixed an issue where notifications using stylized icons had an unexpected amount of padding underneath for high-DPI devices.
• We fixed an issue where receiving a new email notification and tapping on it to open the message wouldn’t open the Mail app or message.
• App developers can now request to pin their primary tile, just like secondary tiles, allowing apps to highlight their awesome live tiles – see this blog post for more info.
• We fixed an issue where on some Lumia phones, such as the Lumia 950, there was no dimming prior to the screen turning off.
• We fixed an issue where pressing the Print Screen key on the keyboard in Continuum wouldn’t take a screenshot of the second display.
• We fixed an issue where preview thumbnails weren’t appearing as expected in the task switcher when using Continuum.
• We fixed an issue impacting apps written for Windows Phone 8.1, where they might crash if certain types of dialogs were open in the app and the touch keyboard came up.
• We improved battery life when OneDrive or similar tasks are running in the background.
• We fixed an issue where the Cortana live tile would appear blank and not showing the Cortana icon for some languages.
• We fixed an issue where pressing the mic button in Cortana, and then immediately pressing the Go button on the keyboard, would result in an “I can’t hear anything” error, rather than speech input being cancelled and a search performed.
• We fixed an issue where the description for the new Apps section of Settings referred to desktop settings rather than mobile ones.
• We fixed an issue where the touch keyboard wouldn’t dismiss after pressing enter when doing a search on the Apps & features Settings page.
• We fixed an issue where the media buttons on a keyboard connected to the phone over Bluetooth would stop working after Bluetooth had been turned off and back on.
• We fixed an issue where Settings might sometimes appear blank except for the search box (until it had been closed and reopened).
• We fixed an issue where the Settings gear would appear pixelated on high-DPI devices when Settings was pinned to Start.
• We fixed an issue where Settings might hang and then crash after tapping on “Fix Me” or “Start\Stop Insider preview Builds” on the Windows Insider Program Settings page.
• We fixed an issue where Settings would crash on the Sign-in options page if you tapped “I forgot my pin”, set it up again, then tapped “remove”.
• We fixed an issue where a string saying SystemSettings.ViewModel.SettingEntry was unexpectedly displayed on the Narrator Settings page.
• We fixed an issue that could result in the Messaging app icon on the lock screen sometimes appearing as a red X as opposed to the expected message bubble.
• We fixed an issue resulting in videos captured with the Camera app unexpectedly appearing with a greyed-out thumbnail in Photos.
• We fixed an issue on recent builds resulting in cellular connectivity sometimes unexpectedly not working after a reboot for Insiders on certain cellular networks.
• We fixed an issue with certain connected Bluetooth peripherals resulting in Groove Music not resuming playing music after ending a Skype call.
• We fixed an issue resulting in the Podcast app being muted after the app had been suspended.
• We fixed an issue resulting in Narrator not being able to read the list of possible tones that could be picked from ringtones when selecting an alarm tone in the Alarms & Clock app.

Known issues for Mobile

• Speech packs will be unable to download on this build.
• The ninja cat emoji display in two characters on the keyboard instead of the expected one.
• Adding a new card / paying with an existing card will not work in Microsoft Wallet.
• Microsoft Edge might sometimes unexpectedly not rotate into landscape mode. If this happens, try quickly locking and unlocking your phone.

Impressed. Just a pity that by the time all this is released there will be very few Windows 10 Mobile phones still for sale for newcomers to use! The Alcatel IDOL 4S with Windows 10 can't come to Europe soon enough, if you ask me! And how about the rumoured HP Elite x3 'lite'?

Of course, in the fulness of time we'll need a summary of what's new going from Redstone to Redstone 2 (Anniversary Update to Creators Update), but we won't have a full feature set or changelog for a while yet.

Anyone with an existing phone that's officially deemed Windows 10 Mobile compatible by Microsoft can join in the fun. The full list of phones includes Lumia 430, 435, 532, 535, 540, 635 (1GB RAM version), 640, 640 XL, 730/735, 830, 930, 1520, Icon, BLU Win HD w510u, BLU Win HD LTE x150q, and the MCJ Madosma Q501. Plus, of course, all the devices which have shipped with Windows 10 Mobile in the last year, of which the Lumia 550, 650, 950, 950 XL, Acer Jade Primo and HP Elite X3 are the highest profile.

In each case:

1. Upgrade to Windows 10 Mobile (if appropriate) using the Upgrade Advisor.
2. After at least one update cycle you should then be on the Anniversary Update (a.k.a. Redstone). Head into Settings/Update & Security/Windows Insider Programme
3. Join the Insiders programme and choose the 'Fast' level in the pick list.
4. Within a few hours your phone should be seeing the build mentioned above and you'll be running next year's mobile OS today. Fun, fun, fun....!