A while back, I found a link somewhere (I don't think it was reddit, but I'm not sure) to a website with a free ear training game.

There were different modes of play:

• They would generate a frequency and you would guess from four choices they gave you.
• They would play a recorded rhythm/melody line, then the same line with a certain frequency cut/boosted and you were supposed to guess which it was.
• They would play pink or white noise, then the noise again with a frequency cut/boosted and you would guess which it was.

It was a really neat little game/training tool, but I can't seem to find it anywhere. It ran right in your browser; no download needed. I found one called Quiztones (or something like that) that looks similar, but that one is only available in the Apple App Store.

*TL;DR: If anyone knows of any (preferably free) ear training tools, I know of a few people who would benefit :) *

Edit: It was definitely the Quiztones demo. Excellent little app. I may even consider buying the full product. Thank you all for the input!

P.S. Pun intended :)