Its a simple tool to calculate how much % profit you could have made if you had invested in any of altcoins/cryptocurrency in past.
Spend Bill Gates' Money is a web-app that lets you calculate all the different sorts of items you can buy & sell using Bill Gates' money.
Networth is an app that helps you keep track of your assets and liabilities.
The idea is simple: you put in how much crypto you own + your net worth WITHOUT crypto. The site will fetch current prices and do the calculations for you. It works with the 10 biggest crypto currencies (by market cap): Bitcoin, Ethereum, Ripple, Litecoin, Dash, NAM, NEO, IOTA, and Monero.