Are Sky Caddie's USGA approved?

Answer 1

The answer is a definite maybe.

The USGA rules do not allow sky caddies.

But, there is a clause that says the local golf organization may allow them.

But, they can only show distances. They are not allowed to show wind speed, direction, temperature, or any other information.

Decision 14-3/0.5:
"A Committee may establish a Local Rule allowing players to use devices that measure distance only. However, the use of devices that gauge or measure other conditions that might affect a player’s play (e.g., wind or gradient) is not permitted.
In the absence of such a Local Rule, the use of a distance-measuring device would be contrary to Rule 14-3. (New)"