I second this app, I'm a big fan of the campaign finance reform score. If you want an easy way to fight the citizens united ruling, this is it.
Also want to give a shout out to https://www.opensecrets.org. their site isn't as easy to use as goods, but the have a lot more data and if you can't find info about a company or politician on goods you can usually still find it on open secrets.
I think 3 is the most useful. You can use it to reach things just out of your height range and maybe as a party trick. I'm sure there are other uses for it too, given enough time I could probably think of some other uses too.