The MagSafe Battery Pack is now available for Apple's iPhone 12 range. One of the battery packs costs $99 and are available for purchase on Apple's website right now. The website indicates that delivery will take place between July 22nd and July 26th for me.
Apple has previously produced iPhone battery covers, but the latest battery pack uses integrated magnets to attach to the iPhone 12 phones. It will also function with the iPhone 12, iPhone 12 Mini, iPhone 12 Pro, and iPhone 12 Pro Max.
Since this item is merely an attachable pack, it doesn't come with any other functions for your phone than providing you some extra power, unlike the iPhone 11 battery cases, which included a real camera shortcut button. However, assuming it works like the MagSafe wireless charger, you might be able to use the pack to charge your AirPods or other Qi-enabled gadgets.
According to Apple, the pack can charge up to 15W, so it will be one of the fastest way to charge your phone. According to Apple's support website, the battery requires iOS 14.7, which isn't available at the time of writing this article. Given Apple's website lists delivery dates for the battery pack as early as July 22nd, it appears that an update to support it will be released shortly.
Apple also sells a magnetic wallet that can be attached to the back of your phone.