Developer Simon Gladman today demonstrated (via Jeff Benjamin) the use of the iPhone 6s display as a way to compare weights of an object, here denoted in a percentage of touch, on Apple’s 3D or Force Touch display.
The app called “Plum-O-meter” for obvious reasons is currently a jailbreak option for tinkerers.
I think it is unlikely that this will hit the Official App Store because it likely makes private API calls to acquire the data. However, it does show yet another device the iPhone could one day replace. Full video follows.
Update: Huawei, which announced a “Force Touch” phone a few weeks before Apple, has a scale app on their phone. Hadn’t seen this, where’s the App Store app then?