The plugin exposes most of MobileDetect's methods, and can be used in your Twig:

{{ craft.deviceDetect.isMobile ? 'I am mobile.' : 'I am not mobile.' }}

Detects all mobile devices, both phones and tablets

{{ craft.deviceDetect.isMobile }}

Detects specific devices, either phones or tablets

{{ craft.deviceDetect.isTablet }}
{{ craft.deviceDetect.isPhone }}

Detects specific OS

{{ craft.deviceDetect.isiOS }}
{{ craft.deviceDetect.isAndroidOS }}

Detects user agent

{{ craft.deviceDetect.getUserAgent }}

Device Detect

Version 1.0.1