Absolutely! The app lives in my phone's "games" folder. I have a relatively small amount of money, just enough that it would sting a bit if I lost it all. I find that even having a tiny stake in things makes learning about investing and finance actually interesting, whereas the majority of my invested assets are all "Vanguard, take the wheel"
+ This. I keep a similar smaller trading account where I effectively gamble with stock picking. I do this as I enjoy researching and understanding businesses and find things more interesting, and you see opinions more honestly when I put money where my mouth is. And it helps you stay engages with your reading. I leave the 'retirement' investments elsewhere.