Measures is an iPhone conversion app by German developer Neuwert Media, which includes all of the standard conversion categories but differs from other apps mainly in its interface and usability.  Measures has three scroll wheels (category, converting from, converting to) and numeric touch keys for value selection, it looks like a great tool but after trying Measures out, this interface makes conversions slightly more time-consuming than some other apps like a2zpro or Units. (…)

With so many conversion apps available at the app store it’s hard to choose. MyConvert by developer Lu A Oo is based on the earlier iConvert and it includes several user-requested units, which make it slightly different than some other conversion apps out there. (…)

a2zpro is the successor to a2z from UK iPhone app developer Westernits and it is a truly innovative tool as far as conversion apps are concerned. Upon every opening of a2zpro the exchange rates are updated for the currency converter, which provides 154 categories with live data from Yahoo!. The currencies work slightly different than in other apps since the user selects the currency and amount and the other 153 conversions are shown underneath (no from-and-to selections are needed and the page is not limited to only a few units).

Converter, by developer Unitconvertr, is a simple and easy-to-use conversion tool that supports 172 units across 15 categories and turns out to be a more colorful and elaborate version of the free conversion app Units. While converter does not support a currency conversion it includes some units that most others lack. (…)

Units, like its namesake, is a handy conversion app but while the name is the same, the features are very different. First off Units costs $0.99 while the app is free and the price does not equal better quality. (…)

Units by UK developer TheMacBox is a great and easy-to-use conversion app, which provides most units that anyone who is not a professional engineer would ever need. The main page of the app allows you to select the desired unit, leading the user to the next page, which shows several conversions at once with the option to edit the list of conversions for some units like currencies.