Today’s a big day for Windows fans. Not only did Microsoft officially kick off the Windows 10 Mobile rollout for Windows Phone 8.1 devices, but it’s also pushing a new Insider Preview update to testers.

Windows 10 Mobile Insider Preview Build 14921 is now rolling out to users in the Fast ring, up from build 14283 that arrived last week. This new build contains a lot of new goodies for PC users — including Microsoft Edge extensions and pinned tabs — but there are some goodies in there for mobile users, too.

Included in build 14921 is an updated Alarms & Clock app with an improved design and the Feedback Hub, which is a combination of the Insider Hub and Windows Feedback apps. 

Also inside build 14921 is an updated Maps app with a more lightweight, consistent UI and several new features, including one-tap access to search and directions from anywhere on your phone, the ability to minimize search results and directions, Cortana turn-by-turn directions, offline support for favorites, and more. The full list of Maps improvements looks like this:

• One-tap access to search and directions from anywhere, even on your phone. This is great especially for one-handed use.
• You can view multiple searches and directions at the same time, on the same map as they are layered on top of each other and you can use tabs or the map to switch between them.
• You can now minimize search results, directions, and location info to enjoy more of the map, while keeping them in easy reach.
• You can see labels for your search results directly on the map. No more numbers to match between the map and the list.
• Cortana will give you turn-by-turn directions (if Cortana is enabled).
• We have improved the logic for nearby searches so you should see better (closer) results.
• We have added the ability to search for your favorite city in the 3D cities list so no more scrolling forever to get to the city you want.
• You can now access your favorites offline and add notes to them.
• We have updated the turn-by-turn design to improve glanceability and landscape layout.

Here are the mobile fixes included in build 14921:

• We fixed the issue where connectivity to older Wi-Fi networks using the WEP encryption security method may be broken.
• We fixed an issue resulting in slower text input speed the more words were typed.
• We have improved Word Flow recognition of longer words.
• The All apps list has been updated to now follow the “Make Text Larger” ease of access setting.
• We fixed an issue where Settings would sometimes list unresolved app names under Extras.
• We fixed an issue where touch targets could be out of alignment in the Photos picker.

And the known issues in build 14921:

• If you reset your phone on this build (Build 14291) and restore your phone from a backup, restore will fail to install apps from your backup’s apps list leaving blank grey titles on Start. If you delete the grey tiles and attempt to reinstall the same apps from the Store, you will not get app data restored. The next backup will over-write the app backup data as well. To avoid hitting this bug, avoid resetting your phone on this build. If for some reason you do need to reset your device on this build, don’t restore your phone from a backup and you should turn off backup for apps and OS data to avoid creating a corrupt backup via Settings > Update & Security > Backup.
• If you have a Microsoft Band 1 or 2 paired to your phone, it will no longer sync after updating to this build due to a system API failure that occurs after the update. If you want to get your Band syncing with your phone again – you can temporarily change the language of your phone as a short term workaround until we release a fix. Additionally, you can also choose to reset your phone to get out of this state – however you may experience this update issue again with the next build until we fix this issue. This issue may also impact Skype video and audio calls.
• The Gadgets app will not detect the Microsoft Display Dock on phones running Windows 10 Mobile Insider Preview builds, and thus cannot update the firmware version. If you have a dock which has already been updated to version 4 then this will not affect you. If you have a dock that has not been updated, then you may experience some minor issues with USB-C stability. You will still be able to use your dock and Continuum.
• There is a new option under Settings > Update & security for Windows Insider Program. This is a work-in-progress option to improve managing your Windows Insider Program settings on your device. Right now, if you go to this option it crashes the Settings app. Please continue to use the Windows Insider app to manage your settings for now.