This is the BLE Live Graph example. It allows a Gen 3 device to communicate directly with your web browser if you have:

Here's a video of it in action. Note the graph at the top of the screen updates in real time as the potentiometer is turned.

You'll need the circuit and code from the ble-potentiometer example, so go ahead and flash that code to your Gen 3 Particle device (Argon, Boron, or Xenon), come back, here, and Click the Start button at the top of the page to begin.

Just View Source on this page to get the HTML and Javascript necessary to do Web BLE!

It's based on the livegraph demo, but that version uses Wi-Fi, and requires a node.js server and setting up IP addresses.