In the same way that car tires are meant to be kept at a precise air pressure, balls made for organized sports are likewise designed to be used at a specific hardness. That's why the TorrX was invented. It's a portable electric pump, that automatically inflates or deflates a ball in order to reach a given pressure.
To use the TorrX, you start by pushing in/twisting its protective end cap to power it up, and to reveal its needle. Once that needle is inserted into the ball's air valve, the pump reads the ball's air pressure and electronically displays it in your choice of BAR or PSI.
In Manual mode, you can then raise or lower that pressure by pressing the + or – buttons. In Auto mode, however, you first key in the target pressure, and then just press the A button. The TorrX will automatically pump in or release air, until that pressure is achieved.
The water-resistant device is powered by a USB-rechargeable lithium-ion battery, one charge of which should allow for approximately 50 fillings of soccer balls, basketballs, volleyballs or footballs. A full recharge of the battery takes about 90 minutes.
The designers are currently raising production funds, on Kickstarter. A pledge of US$49 will get you a pump, when and if they're ready to go. The planned retail price is $80, which is close to that of the Airgun, a somewhat similar existing product.
A demo of the TorrX can be seen in the pitch video below.
Sources: TorrX, Kickstarter