Human is an iPhone app (no affiliate link) that monitors movement. It tracks physical activity throughout the day with the objective of encouraging an active (and, thus, healthy) lifestyle. And it is free.
While we are eagerly tracking how many minutes we have walked or cycled, grateful for this boost to our health from a free app, the company behind the app is amassing the data. Through a process detailed here, the company produced and released visualisations of the activity of its users.
The visualisations are truly stunning. The visualisations are also a reminder that, when the product is free, we become the product.