While there's nothing wrong with a crowded nightclub or bar, sometimes you just want to get away from everything, maybe find a quiet spot to relax. Unfortunately, there's no real way to do that without actually going to the place first: your favorite little hole-in-the-wall could turn into a packed house overnight, and there's no way of knowing until you actually arrive.

Or rather, that used to be the case. Now, there's a way to tell just how packed a place is before you even leave the house.

The Density sensor is, at its core, a "people counter." Basically, it's a tiny sensor that sits in a door frame and keeps track of everyone who passes through its field of view. The tech is nothing new, as break-beam sensors have been used in everything from garage doors to elevators — but it's the real-time population tracking that separates Density from anything else like it.

As the Density homepage demonstrates, there are plenty of business uses for population tracking. Want to know when your restaurant is empty? Just take a look at your Density tracking data, and you'll know when the kitchen is dead. Worried that your store is in a bit of a slump? Let Density automatically generate sales based on population changes.

In fact, a number of businesses are already using Density: Workfrom uses the system as a way to let remote workers know where there's a free seat, while Requested lets users generate discounts once a restaurant hits a certain population. Even the University of California in Berkeley is using Density as a way to let students know when certain facilities are overcrowded.

Then, of course, there are more personal uses. If you don't feel like fighting for gym equipment, tables or space in general, you don't have to — just check the Density app, find your location and you'll be able to see just how full (or empty) wherever you're headed is.

The best part is that, because Density is built on preexisting technology, it's not all that expensive for businesses to adopt. Combine that with ease-of-use, flexibility and small size, and it's likely that more and more locations will start adopting Density.

For everything on the Density system, app and price, just head on over to the official website.