Sunnytrail [1] offers a service for SaaS providers to track key metrics once they have paying customers. However, they don't (yet) offer the most interesting part of your idea, comparing results against others in your industry.

It's a fascinating and a non-trivial problem you're addressing here and I'm interested to see how you approach it. Get it right and it could add huge amount of value.

The three toughest challenges as I see it:

1. Standardising metrics across a broad range of different business stages, verticals and models to provide a meaningful number (compare apples with apples).

2. Helping users to identify appropriate metrics from each of the AARRR categories. I.e. indicative and actionable.

3. The perennial problem of identifying unique users so that the behaviour of new or repeat visitors can be accurately measured prior to signup. IP addresses are not reliable (NAT & dynamic IPs), cookies can be flushed and potential customers have opportunity to access a service from a variety of devices - I know the folks at KISSmetrics put a lot of work into this.

[1] https://www.thesunnytrail.com/

edited for readability