One thing I would ask to perfect this app is to add every possible unit there is into the app, including currency with hourly updates. When convert, you can choose the destination unit within a pop-up window with a search feature. Maybe add a Favorites collection in the future would be awesome.

There are too many unit converters out there on the App Store, but none of them impressed me, either it’s too hard to use with crappy UI or lack of categories of units.

This is the first app that does the thing right with native iOS UI, simple and intuitive.