It emails people with some frequency between weekly and monthly, and it only asks you a few questions every time. Mostly it's a 1-10 scale thing, with cute little graphics.
It also asks open ended questions where you're told the answers are anonymous. That's all well and good, but if your manager can't figure out who's who from the tone of the message, they're a new manager.
And sure, it sounds like a great idea to spot issues. The instant two managers compare scores, or worse, are compelled to compare scores, all bets are off on it's usefulness. Then when you have a meeting where a high level manager painfully asks for input on how to make things better from the entire team while going over each chart in painful detail, the clear goal every individual contributor has is to just pick 8 or 9 and make the stupid meetings stop.