Latest Facebook 50 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/50.0.0.10.54;] Android 4 Z777
Mozilla/5.0 (Linux; U; Android 4.3; en-us; MT2L03 Build/HuaweiMT2L03LITE) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Ascend Mate 2
Mozilla/5.0 (Linux; U; Android 4.2.2; de-de; SM-C105K Build/JDQ39) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Galaxy S4 zoom
Mozilla/5.0 (Linux; U; Android 4.1.2; es-us; ZTE-Z740G Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Z740G
Mozilla/5.0 (Linux; U; Android 4.1.2; es-us; SCH-I200PP Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Galaxy Stellar
Mozilla/5.0 (Linux; U; Android 4.1.2; es-us; GT-I8260E Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Galaxy Core
Mozilla/5.0 (Linux; U; Android 4.1.2; es-ar; LG-P778 Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 P778
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/50.0.0.10.54;] Android 4 Z740
Mozilla/5.0 (Linux; U; Android 4.1.2; en-us; SCH-I200PP Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Galaxy Stellar
Mozilla/5.0 (Linux; U; Android 4.1.2; en-us; LG-E971 Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 E971
Mozilla/5.0 (Linux; U; Android 4.1.2; en-us; LG-AS780 Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 AS780
Mozilla/5.0 (Linux; U; Android 4.1.2; en-au; LG-E975K Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Optimus G
Mozilla/5.0 (Linux; U; Android 4.1.2; en-au; HTC_0P6A1 Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 0P6A1
Mozilla/5.0 (Linux; U; Android 4.1.2; en-au; GT-I9100T Build/JZO54K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Galaxy S II
Mozilla/5.0 (Linux; U; Android 4.1.1; en-us; HUAWEI C8813D Build/HuaweiC8813D) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 C8813D
Mozilla/5.0 (Linux; U; Android 4.0.4; en-us; LG-E970 Build/IMM76L) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.6.52;] Android 4 E970
Mozilla/5.0 (Linux; U; Android 4.0.4; en-us; HTC One VX Build/IMM76I) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 One VX
Mozilla/5.0 (Linux; Android 5.1.1; SM-N910G Build/LMY47X; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/45.0.2454.95 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 5 Galaxy Note 4
Mozilla/5.0 (Linux; Android 5.0.2; LG-D724 Build/LRX22G; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/50.0.2661.86 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 5 G3S
Mozilla/5.0 (Linux; Android 4.4.2; SM-910U Build/KOT49H) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/30.0.0.0 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/50.0.0.10.54;] Android 4 Galaxy Note 4