User Agent

Mozilla/5.0 (iPhone; CPU iPhone OS 10_3_3 like Mac OS X; en-US) AppleWebKit/537.51.1 (KHTML, like Gecko) CriOS/23.0.1271.100 Mobile/14G60 Safari/7534.48.3 UCBrowser/11.3.5.1203

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

Browser - UC Browser

UC Browser

Version11.3 @ 32 bit
DeveloperUCWeb Inc.
ParentUC Browser 11.3 for iOS
Device TypeMobile Phone

Act as 

Crawler No
Fake No
Anonymized No

Device - Apple

BrandApple
ModeliPhone
Platform apple 10.3 (32 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