A tool to help decide what browsers you should be developing for.
Using your statistics from Google Analyics, browserguide will assess your website's traffic and let you know what devices and browsers your customers are using. From there, you will be able to define varying levels of support. For example, you might want to support functionality above 1%, but only design and functionality above 3%.
Browserguide will then generate a report detailing what devices you should test on, and what browsers you should be supporting. You can even print the report out and wave it around in your next standup to convince your team you can definitely stop supporting IE8 now.
This tool is not meant to set hard and fast rules for your development process. You should use this simply as a guide. It can't tell if your client's entire office runs Windows XP because that one tool everyone must use was abandoned 10 years ago and doesn't work on any other OS. This would show up as a miniscule piece of the traffic, but is still argueably more important that what is on the rest of your list.
To get started, visit WebsiteNameTBD.com