Latest Facebook 54 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; U; Android 4.3; en-us; ZTE-Z777 Build/JLS36C) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Z777
Mozilla/5.0 (Linux; U; Android 4.3; en-us; ZTE-Z669 Build/JLS36C) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Z669
Mozilla/5.0 (Linux; U; Android 4.2.2; es-us; GT-I9080L Build/JDQ39) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Galaxy Grand
Mozilla/5.0 (Linux; U; Android 4.1.2; pt-br; LG-E475f Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Optimus L1 II
Mozilla/5.0 (Linux; U; Android 4.1.2; pt-br; LG-E470f Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Optimus L4 II
Mozilla/5.0 (Linux; U; Android 4.1.2; pt-br; LG-E465f Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Optimus L4 II
Mozilla/5.0 (Linux; U; Android 4.1.2; es-uy; LG-E980h Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Optimus G Pro
Mozilla/5.0 (Linux; U; Android 4.1.2; es-us; ZTE-Z998 Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Z998
Mozilla/5.0 (Linux; U; Android 4.1.2; es-us; GT-I8260L Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Galaxy Core
Mozilla/5.0 (Linux; U; Android 4.1.2; es-us; GT-B5330L Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Galaxy Chat
Mozilla/5.0 (Linux; U; Android 4.1.2; es-pa; LG-E980h Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Optimus G Pro
Mozilla/5.0 (Linux; U; Android 4.1.2; es-mx; LG-E980h Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Optimus G Pro
Mozilla/5.0 (Linux; U; Android 4.1.2; es-ar; LG-P712 Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Optimus L7 II
Mozilla/5.0 (Linux; U; Android 4.1.2; en-us; ZTE-Z995 Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Z995
Mozilla/5.0 (Linux; U; Android 4.1.2; en-us; ZTE-Z740 Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Z740
Mozilla/5.0 (Linux; U; Android 4.1.2; en-us; ZTE-V72A Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.1 Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 V72A
Mozilla/5.0 (Linux; U; Android 4.1.2; en-us; GT-S7710L Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Galaxy Xcover 2
Mozilla/5.0 (Linux; U; Android 4.1.1; es-us; ZTE-Z993 Build/JRO03C) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Z993
Mozilla/5.0 (Linux; U; Android 4.0.4; en-us; LG-LS860 Build/IMM76I) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 LS860
Mozilla/5.0 (Linux; U; Android 4.0.3; pt-pt; Transformer TF101G Build/IML74K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Safari/534.30 [FB_IAB/FB4A;FBAV/54.0.0.23.62;] Android 4 Transformer TF101G