Kilowhat? So if you've haven't brushed up on your math, here's a tip: there's an app. For diagnosing cancer, depositing checks and throwing birds at evil pigs.
I've seen more smartphone apps than I care to review, but these are a few of my personal favorites for hitting the ground running.
Android: Exchange Rates
Exchange Rates is a free download in the Android Market, and it does exactly what it implies, which is convert currencies. There are several options here: you can track multiple currencies, order them, see currency charts, invert rates and more. The app automatically checks for the latest rate when you open it, but if you're not connected to a data network, it will use the last updated information. It's ad-free, but what makes it really easy to use is how easy to see what a $3 USD burger cost in HKD, GBP and MXN instantly.
iOS: Convert Everything Free
I've previously covered this app elsewhere before, and its gone through several changes since I've first picked it up. It's ad-supported, but its core functionality hasn't changed. It'll help you go from imperial to metric, Fahrenheit to Celsius and can also convert currencies seamlessly. It's just as customizable, and while the UI isn't as smooth as Exchange Rates, it does add some bells and whistles in being a pretty decent all-in-one converter. (Update: If you're looking just for a great currency converter, and only that, we'd suggest Oanda currency converter.)
These two apps are not all-inclusive of everything that's out there -- for example, Exchange Rates lacks the ability to convert between measurement systems, but it does what it does really well. And for everything else, there's calculators and simple good ol' math skills.
