Latest Amazon Kindle Fire HD 8.9" 4G user agents:

User Agent	Browser	Platform
Mozilla/5.0 (Linux; U; Android 4.0.4; en-us; KFJWA Build/IMM76D) AppleWebKit/537.36 (KHTML, like Gecko) Silk/3.68 like Chrome/39.0.2171.93 Safari/537.36	Mobile Silk 3	Fire OS 3
Mozilla/5.0 (Linux; U; Android 4.0.4; en-us; KFJWA Build/IMM76D) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Safari/534.30	Android Browser	Fire OS 3