LevelFlight allows you to fly perfectly level with a key press. It does this by taking advantage of the fact that you can set your pitch limit (how much you can angle the camera up or down) to zero, meaning you can move in a perfectly straight line while flying or swimming.
Usage:
-- Bind a LevelFlight setting in the key bindings. Pressing the key will force you to fly at that level once you attempt to move. Pressing it again will allow you to fly free once more.
-- You can also create a macro containing "/click LevelFlightButton" to toggle level flight. The new buttons for dragonriding are LevelFlightButtonHalf, LevelFlightButton1, and LevelFlightButton5.
-- Chat output and automatic pitch reset can be configured at the top of LevelFlight.lua.
LIMITS:
-- Changing your pitch limits your camera motion to only that amount of degrees up or down. Turning off level flight restores the full range of motion.
-- If you have multiple LevelFlight buttons bound, the addon will always reset the camera to full motion before changing to a different limit. This is by design as we apparently can't query what the current pitch limit is.