Untappd

One of my most often used smart-phone apps and it's free (I love free).   Untappd allows me to keep track of what beers I've had, where I've had them and how I liked them.  Aside from my personal beer diary, Untappd taps (pun intended) into the power of a hopping (pun again) crowd so I can find a local pub that's serving my favorite brew.

https://untappd.com/