User Agent

Mozilla/5.0 (iPhone; CPU iPhone OS 15_1_3 like Mac OS X) AppleWebKit/594.3.15 (KHTML, like Gecko) Version/15.1 Mobile/15E148 Snapchat/12.22.0.27 (like Safari/594.3, panda)

This user agent belongs to Safari. Apple Inc developed this Browser. This Browser run on iOS and it renders web contents with WebKit on iPhone.

Browser - Safari

Safari

Version15.1 @ 64 bit
DeveloperApple Inc
ParentMobile Safari 15.1
Device TypeMobile Phone

Act as 

Crawler No
Fake No
Anonymized No

Device - Apple

BrandApple
ModeliPhone
Platform apple 15.1 (64 bit) by Apple Inc
Mobile Yes
Tablet No

Capabilities

Rendering EngineWebKit by Apple Inc (For Google Chrome, iOS (including both mobile Safari, WebViews within third-party apps, and web clips), Safari, Arora, Midori, OmniWeb, Shiira, iCab since version 4, Web, SRWare Iron, Rekonq, and in Maxthon 3.)
Pointingtouchscreen
Javascript Yes
CSS Yes Version: 3
Cookies Yes
Tables Yes
Frames Yes
IFrames Yes
Background Sounds No
Java Applets Yes
VB Script No
Activex No