The average phone case is basically a piece of plastic that protects your device when you drop it. But what if you could add modular features to your iPhone like a heart rate monitor, a grappling hook, or a backup battery? Now you can.

Moscase comes to use from Hungary and is being crowdfunded to the tune of $150,000. The case protects your iPhone 6 or 6 Plus and has a removable back. You can quickly snap out the back and replace it with one of the optional tools, turning your case into a breathalyzer, a speaker, or even an e-ink screen for reading.

The device comes in two parts. The bumper without a backplate can sense your pulse, temperature, and body impedance AKA how fat you are. It costs $129 and comes with a “passive” backplate. A model with one “active” backplate costs $219. I think the e-ink solution is the coolest, allowing you to read on the back of your phone, saving your battery for more important work.

Obviously all this is pretty pricey but it’s a cool way to add lots of sensors to your iPhone for not much money. I met one of the founders in Budapest and he told me that they found traction at home but not abroad and, when they ship in June, you’ll have plenty of time to play with your new case before Apple releases the iPhone 7 with USB-C and a huge rear camera.