I have shares in a couple of companies on seedinvest, and there are some other companies like this I've seen but not tried. Source: about 1 year ago

Http://seedinvest.com is a crowd-sourced private equity platform. I put $2k into 10 different companies several years ago through their autoinvest feature (you may be noticing a trend), and so far 2 of them have IPO'd at something like 8x the valuation I paid for. Meanwhile, at least one has been restructured like 8 times down to like 0.1% my original investment. The past is not a predictor of the future. ... Source: over 2 years ago

If you store all your coins in a single wallet, such as exodus, then that's the easiest way to keep track. If your coins are split across different wallets and exchanges though, I use this on windows and it seems to be available on mac as well - you just manually enter your hold and it updates prices every few seconds :). Source: about 3 years ago