Google analytics — This is all the analytics you need right here and it's free.
MixPanel — "Deeply understand every user's journey with instant insights for everyone on mobile and web." Can track individuals with great precision. Starts at free.
Kissmetrics — Focus on deeply engaging with individual customers
Hotjar — See a visual representation of your user's clicks, taps, and scrolling behavior, free up to 2000 clicks per day.