I just found another major use for the iPhone. After I tell you what it is, you will look for reasons to constantly pick up your iPhone.

The iPhone can be turned into a dumbbell. Every time you pick up the iPhone, you will be giving yourself a good workout. This is all made possible by ToneFone, a product of the UK-based company DesirableBody. It’s the world’s heaviest iPhone case. It is available for the 5 and 5S in a 2.2 pound and a 3.3 pound version. It’s rubber-coated and constructed of 100 percent British steel.

Priced around $38 and $42 respectively, the ToneFone can be shipped to the U.S. for around $11.50.

I know you think this product sounds ridiculous but several tech reporters actually bought the ToneFone. They say they love it because they are always in workout mode. That’s good news for people who make their living sitting on their tush.