Calvertr (US$2.99) is a clever evolution of the standard calculator and conversions app. As a calculator it is pretty basic, but where it really shines is in its conversion abilities. As a currency converter, for example, it supports 157 different monetary systems around the world. Categories or types are searchable, conversion data can be shared with friends, and the app lets you share a note along with results. There are literally conversions for almost anything: astronomical, calendar days between dates, radioactivity, ROI, fuel consumption, and the list goes on and on from the mundane (like calculating tips at restaurants) to the more arcane like viscosity and torque conversions.
The app supports AirDrop sharing and printing if you are so equipped. Calvertr also supports the new iOS 8 Notifications Center widgets, which lets you select your most-used functions and have them available instantly in Notifications Center.
The look and feel of the app is attractive, with screens that are easy to read and understand. When you first launch the app there are help screens to get you started. To go back to any previous page, just flick the screen to the right.