The most minimalistic analytics system I could imagine. Stores only page loads, no personal information. Tracks by loading a simulated dead pixel into your site. Check your stats at https://deadpixel-11ef1.firebaseapp.com//
At the most basic level you can just load the tracking pixel and style it.
<img src="https://deadpixel-11ef1.firebaseapp.com/pixel.png" />
I tend to use this snippet at the bottom of the document.
<script>
;(function() {
'use strict'
var pxl = document.createElement("img")
pxl.style.width = '1px'
pxl.style.height = '1px'
pxl.style.background = 'black'
pxl.style.position = 'fixed'
pxl.style.left = '99.7%'
pxl.style.top = '0.3%'
pxl.style.zIndex = '999999999'
pxl.src = 'https://deadpixel-11ef1.firebaseapp.com/pixel.png'
document.body.appendChild(pxl)
})()
</script>
The world is your oyster.