Latest Firefox 28 user agents:

User Agent	Platform	Device
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:28.0) Gecko/20150151 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8986 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8897 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8763 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8713 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8689 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8551 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8418 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8363 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8349 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8341 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8336 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8237 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8158 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8155 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8098 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8093 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 8079 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown
Mozilla/5.0 (X11; Ubuntu; 7969 ; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0	Ubuntu	Unknown