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App Review: Convert — Apparently Form Does Not Equal Function


Convert, an app for converting an array of different units, looks great and, in theory, should be quite useful. Unfortunately, the bad outweighs the good on this one.

The iPhone isn’t just about gaming and entertainment. Admittedly, I’ve got two screens worth of music and gaming apps, another screen for news, books and recipes, and then a screen dedicated to file-sharing and chat.

On my fifth and final screen, however, is a selection of software tools. There’s the basics, like Calculator and WeDict, sat alongside GPS-tools such as Locly and HearPlanet. Until now though, there was no unit converter.

The clever people at Polar Bear Farm have created Convert, a unit conversion tool that marries a variety of seemingly esoteric units — to the layman — with a polished interface.

With quite a history behind them, having launched in 2007, Polar Bear Farm is no strangers to app development. Notable past releases included Nice List, a stylish holiday gift manager, and Note Pad, a replacement to the iPhone’s own Notes app, upping the game with graphical flair and desktop syncing.

Then there’s Telegram, filling the iPhone voice-messaging void by allowing users to send short audio messages to each other.

The point is, Polar Bear Farm is an app developer who seems to specialize in creating tools that manage data and make life easier. And what’s more, these tools are always visually stunning.

Units and Values

Moving on to Convert, the most exciting thing when first opening the app is the aesthetic. It’s not at all iPhone-esque — gone is the Apple-aesthetic we all adore. Instead is a reductionist approach — metallic and digital, calling to mind expensive electronic tools created for specialists.

This may not be too far from the truth though as, while the app is indeed visually stunning, it also seems to pack in an array of esoteric units for converting. The units are separated in to ten different classes: Angle, Area, Length, Mass, Power, Pressure, Speed, Temperature, Time and Volume.


All the basics are present and correct too, so entering the Length section will bring up Inches, Kilometers, Miles and Feet, among other conversion options. Notably, however, the app does not convert currency, something which — as an iPhone user who travels frequently — would have proved incredibly useful.

Perhaps more importantly, the app incorporates a diverse range of less commonly-used unit-types, such as radians, nautical miles, and drams. Unfortunately, Delorean owners will be disappointed to find that there is no option to convert Gigawatts.


Although the UI isn’t quite as intuitive as it should be, the actual conversion process is incredibly easy. Select the unit to convert from and then the unit to convert to, then tap the numbers on either side of the equation, enter the new figure and instantaneously the equation adjusts to display your answer.

Comparing Problems

When I initially heard about the app’s $1.99 price tag, I felt somewhat unsure, questioning whether a unit converter is really worth two bucks. For my own conversions, I use Google. It’s free to use, although admittedly somewhat clunky on the iPhone and requiring a data connection.

In comparing Convert to Google’s calculator, I discovered a couple of interesting anomalies. When numbers are displayed, it always expresses them in full, so 596 days in microseconds would be 51,494,400,000,000.


There are, of course, shorter ways of expressing the same value. Google’s calculator outputs 596 days as 5.14944 × 10^13 microseconds (see it here displayed properly). The issue is further compounded with even larger numbers — Convert doesn’t seem to like really big numbers, in fact. It seems if a number is too big for the display, nothing at all is shown. As such, converting 596 days to nanoseconds leaves the display blank (whereas Google has no trouble).

The point is that the tool should be able to handle these kind of equations and express the outputted value clearly to the user. Convert seems to have been designed as much for the layman as for Make enthusiast or even coders and physicists. Esoteric units of measurement are all well and good, but the app should be able to handle esoteric equations too.

Furthermore, there’s some notable competition on sale in the App Store. One app in particular, The Converter, packs in a serious amount of units for converting, including currency conversion too, for 99 cents. However, The Converter (and all of the other conversion apps on offer) certainly aren’t as aesthetically impressive as Convert. I just don’t know if a pretty user interface is enough to warrant an extra buck, though.

Summing Up

With its appropriately stylized visual, so much work seems to have gone in to creating an app that looks professionally produced. The sound design is excellent as well. The app clicks and bleeps just at the right time, giving a satisfying level of tangibility to this digital tool.

However, there seem to be a couple of drawbacks to an app that could be accused of putting form before function. Firstly, despite the range of different units on offer for conversion, in comparison to other (cheaper) apps, Convert actually only seems to provide a paltry selection. The app therefore needs an update that expands the unit library to something much more substantial.


The other issue is with the way the app displays — or occasionally doesn’t display — values. With the user interface so rigidly set as part of the design and the apps current inability to express x to the power of y, it literally leaves no room to display incredibly large numbers. I’m surprised that this issue didn’t get caught in the testing phase.

As the app currently is, despite the fact it looks so gorgeous, I really can’t recommend it. There are cheaper apps out in the store that, while they certainly don’t have the good looks, have the features and the brains to hold their own. Until this app gets a much-needed upgrade, I suggest you avoid it.

8 Responses to “App Review: Convert — Apparently Form Does Not Equal Function”

  1. Recently, there has been a good deal of litigation by the
    FTC against blogs and website promoters
    for not stating advertising profits, or existing
    connections with advertising networks.

    What are your personal thoughts concerning how this could effect
    the blogging world?

  2. I think that’s where the comments section here comes in to it’s own.

    Feedback from our readers is an invaluable part of the review process – we get to discuss, debate and compare apps based upon you using them in the wild.

    Although I think it’s best that we leave Steve’s autocratic hole out of the discussion.

  3. Cousin Dan

    Upon reading this there seems to be something odd afoot. Only ten categories? I have been using converter since before the app store, it was one of my favourites on my jailbroken ipod touch which meant I was happy to part with the couple of quid it cost me upon legitimising. This app has 27 categories in the favourites section, and many many more when you browse them all, I only know this because the article prompted me to check. I have never needed to go beyond the favourites section before.

    It includes currency and goes online and updates to the latest rates. And whilst the aesthetic is not as calculated (haha) as convert, I as a design oriented person have never had any gripes with it, and I think the screen shots you’ve shown us are as ugly as sin personally.

    I think the problem here is that you have reviewed this in isolation, which is fine for a unique product like a game, but when there are multiple solutions available it would be good to do a comparative review. A best of category type thing? Maybe choose the leading few converters, RSS tools, book readers etc. and tell us which to buy. Could the ever increasing app section of TAB handle this? Can you replace that warm paternal autocratic hole that Steve Jobs has left in our lives? Please help us Olly, you’re our only hope!

  4. Yeah dude why does no one ever review Units which is free and handles your nanosecond example as well as currency conversion? And I forgot about the ruler too–thanks. I also like the way all conversion units are displayed when you fill in the units your converting from. One of my favorite apps. $1.99? Yikes!