Glider is a Dragonriding/Dynamic Flight Vigor bar replacement addon for World of Warcraft with custom textures and smooth animations.
Current Gliding Speed is displayed as text as well as visually guided outer shell, if you have the Thrill buff active it will be green, outside of thrill it will be red. If you are currently recharging vigor will be displayed as a animated pulse while gliding and on the ground.
Placement of it can be changed via the Games own Edit Mode under Game Menu (Escape) > Edit Mode, there are also a few additional colors available for you to discover there. You can also show/hide the default UI Vigor there if you want it displayed too.