Tossed this another upvote. This is quite cool and useful! I encourage jobhunters to use this as well - pay 99$ for the month(s) you're negotiating, then cancel when you no longer need it. It's a great investment.
Some caveats:
1) The UI has some bugs
2) Equity data isn't helpful at all, and is outright wrong in some contexts. Only way to fix this is garner more data from the VCs themselves. Unfortunately, flagging or crowdsourcing these values in any way defeats the point of the reliable survey.
OfferLetter.io