Studying for the GRE (again) is a hassle. Honestly, no one wants to pound random mathematical formulas and vocab words into their head. It isn't a healthy way to learn (or re-re-re-learn). The vocab portion in particular is annoying, because certain words (i.e. polemics, hegemony, pedagogy) really have a lot more implications than can be summed up in a few phrases. In any case, I am flash carding my way through the vocab list, so I thought I'd share this great site someone pointed out for me back in undergrad.
So this site is called Free Rice. Essentially, the page shows a word, and you click on the synonym. For each correct answer, 10 grains of rise are donated to the United Nations World Food Program. Apparently, there are other question games up now, but the original vocab game is the most useful for my purposes, and easiest to get to, as it just pops up when you go to www.freerice.com.
Studying vocab is a pain, but it's nice to feel like you're helping someone, even if it is with a minimal amount of effort. So, if you're feeling like becoming more educated, why not support the UN WFP?