Latest Firefox Mobile 28 user agents:

User Agent Platform Device
Mozilla/5.0 (Mobile; rv:28.1) Gecko/28.1 Firefox/28.1 Firefox OS Unknown
Mozilla/5.0 (Mobile; OpenC; rv:28.0) Gecko/28.0 Firefox/28.0 Firefox OS Unknown
Mozilla/5.0 (Mobile; ALCATELOneTouch4019X; rv:28.0) Gecko/28.0 Firefox/28.0 Firefox OS OneTouch4019X
Mozilla/5.0 (Android; Tablet; rv:28.0) Gecko/28.0 Firefox/28.0 Android Unknown
Mozilla/5.0 (Android; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android Unknown
Mozilla/5.0 (Android 5.1.1; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 5 Unknown
Mozilla/5.0 (Android 4.4.2; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 4 Unknown
Mozilla/5.0 (Android 4.3.1; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 4 Unknown
Mozilla/5.0 (Android 4.0.3; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 4 Unknown
Mozilla/5.0 (Android 4.0.1; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 4 Unknown
Mozilla/5.0 (Android 3.2.4; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 3 Unknown
Mozilla/5.0 (Android 3.1; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 3 Unknown
Mozilla/5.0 (Android 2.3.6; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 2 Unknown
Mozilla/5.0 (Android 1.6; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 1 Unknown
Mozilla/5.0 (Android 1.1; Mobile; rv:28.0) Gecko/28.0 Firefox/28.0 Android 1 Unknown
Mozilla/5.0 (Mobile; ALCATELOneTouch4019A; rv:28.0) Gecko/28.0 Firefox/28.0 Firefox OS OneTouch4019A