I realize this is a rhetorical question, but the serious answer is that you can't measure fun (without an EEG?), just proxies for it. Typically these are things like how much time someone spends doing something, how much they spend on it, how much they talk to their friends about it. I'm pretty sure that yes, the dashboard physcab maintains supports these. If you have a better way of measuring fun then you can make several fortunes selling this.