If you have a few minutes to spare check out www.freerice.com. This is a website set up to test your vocabulary and increase your word knowledge. It also donates 20 grains of rice for each word you get right .... or guess right! ... through the United Nations to end world hunger. (I checked it out at Snopes.com and it is for real.)
When I first started the 'game' I thought ... "this is not too bad...I'm smart!" .... then a few more words later I thought ... "oh dear .... I'm not as smart as I thought I was!" .... then at about level 48 - 50 I thought 'dear me ... I better get out my dictionary"
It is a fun way to help out and learn at the same time. Have fun!