Units Plus Converter is a beautifully designed unit converter for iPhone, developed by Alan Mrvica. It is optimized for a wide range of iPhone and iPad models, including the iPad Pro and iPad Mini, and supports iPad Split View.

The app includes 12 categories with a variety of units, including area, currency, data-computer data, fuel-milage, length, power, pressure, speed, temperature, time, volume, and weight-mass. One of the standout features of the app is the ability to convert currency with live updates for 155 world currencies, which are downloaded every 15 minutes when the app is open. The app uses very small amounts of data for each download, around 1-2kb.

Units Plus Converter has a simple and intuitive interface, and swapping between units is easy with the press of a button on the keypad. The app is perfect for anyone who needs a quick and easy way to convert units on the go. However, it should be noted that an internet connection is required for currency conversion.

Overall, Units Plus Converter is a great choice for anyone in need of a simple and beautifully designed unit converter for their iPhone or iPad.