We recommend downloading the RC only on something other than your primary device. Since this isn't the final version of iOS 17.3, these features might be buggy and battery life may be short, and it's best to keep those troubles on a secondary device.

If you're a developer or public beta tester, here are some of the new features you can find in the iOS 17.3 RC. Note that the RC isn't the final version of iOS 17.3, so these might not be the only new features to land on your iPhone when iOS 17.3 is released. There's no word on the public release for iOS 17.3 just yet, but Apple could release the update to the general public next week.

Stolen Device Protection

Apple introduced Stolen Device Protection in iOS 17.3 beta 1, which aims to help protect you and the data on your iPhone. Here's what Apple writes about the new feature:

Testing is now available for Stolen Device Protection. This new feature adds an additional layer of security in the unlikely case that someone has stolen your phone and also obtained your passcode.

• Accessing your saved passwords requires Face ID to be sure it's you.

• Changing sensitive settings like your Apple ID password is protected by a security delay.

• No delay is required when iPhone is at familiar locations such as work and home.

According to CNET's David Lumb, Stolen Device Protection requires you to enter your biometric authentication, like Face ID and Touch ID, multiple times to access some of your sensitive settings and information. This is an optional security feature, but Apple recommends everyone turn it on.

Once you've updated your iPhone, it should prompt you to enable Stolen Device Protection. If you didn't see a prompt or you skipped it for later, you can turn the feature on by going to Settings > Face ID and Passcode and tapping Turn On Protection under Stolen Device Protection.

New Unity wallpaper

In honor of Black History Month, Apple is releasing a new wallpaper, called Unity Bloom, for all devices that run iOS 17.3. According to Apple, the wallpaper shows an outline of flowers that will fill with color once the display is active. 

The return of Apple Music collaborative playlists

Apple announced collaborative playlists in Apple Music at WWDC 2023 in June, and the feature was included in some beta versions of iOS 17.2. Apple removed this feature from the final version of iOS 17.2. With iOS 17.3 beta 1, Apple brings collaborative playlists back, allowing multiple people to edit and control shared playlists in Apple Music. 

And with iOS 17.3 beta 2, Apple introduced the ability to react with an emoji to a song in a collaborative playlist that someone else added. That way you can let someone know instantly if you like a song or not in the playlist.

Here are the full release notes for the iOS 17.3 RC:

About This Update

Stolen Device Protection

Stolen Device Protection increases security of iPhone and Apple ID by requiring Face ID or Touch ID with no passcode fallback to perform certain actions.

Security Delay requires Face ID or Touch ID, an hour wait, and then an additional successful biometric authentication before sensitive operations like changing device passcode or Apple ID password can be performed.

Lock Screen

New Unity wallpaper honors Black history and culture in celebration of Black History Month.

Music

Collaborate on playlists allows you to invite friends to join your playlist and everyone can add, reorder, and remove songs.

Emoji reactions can be added to any track in a collaborative playlist.

This update also includes the following improvements:

AirPlay hotel support lets you stream content directly to the TV in your room in select hotels.

AppleCare & Warranty in Settings shows your coverage for all devices signed in with your Apple ID.

Crash detection optimizations (all iPhone 14 and iPhone 15 models).

Some features may not be available for all regions or on all Apple devices. For information on the security content of Apple software updates, please visit this website:

https://support.apple.com/kb/HT201222

Those are some of the new features developers and beta testers will see in the iOS 17.3 RC. That doesn't mean these are the only features coming to the next iOS update, or that these changes will stick when iOS 17.3 is released to the public.