Insidebike is live
The site is live, with one tool on it: a gear calculator.
Give it your chainrings, sprockets and wheel and it shows how fast every gear goes at three cadences — grinding, normal and spinning. It also rates the gap between each gear and the one before, and can order the gears the way you would actually ride through them rather than the way they sit on the bike.
There is a lookup for both ends of the drivetrain, so you can find your cassette or chainset by brand, model or size instead of typing eleven numbers. Every result is a link: change anything and the address bar keeps up, so you can bookmark your own bike or send someone the exact table you are looking at.
If a number looks wrong to you, it may well be. Tell us and we will fix it and say so here.