I want to take a couple minutes to talk about software design in the context of our latest update, Penultimate 1.2. There’s a lot to like in this update (colors, languages, to say nothing of bug fixes), but my personal favorite feature is the “magic” eraser. 

We get a LOT of email from passionate users. One thing that we’d heard often was “Give me choices for the size of the eraser!”. People using styluses, as well as those with less stubby fingers (than, say, mine), were discovering that they couldn’t easily do detail erasing with the one-size-fits-all original. Drawing software will often give a few options for the size of an eraser, letting the user pick depending on the task. I tried this, briefly. It was competent, but clunky. 

Then I realized: Why should you have to choose which eraser size you want? Isn’t there enough information—in the touch gesture and in the ink data— to know what you’re trying to do most of the time? Hey, this is Twenty-Ten, and even if my hoverboard hasn’t arrived just yet, at least I should be delighted by technology doing my work for me. So several hours of intensive fiddling later, I had a working prototype: a magic eraser that’s always the size you need it to be. If you’re carefully rubbing out small details, it does that. If you want to erase a huge swath of the page, though, just a few swipes can do it.

Because I was afraid people wouldn’t understand that the size changes, I made it visible as a pink circle that morphed size as your finger moved. But this looked kind of dumb, as my reliable alpha tester John pointed out. “And you shouldn’t need that if it really feels natural.” He was right. The eraser went back to being invisible, got tweaked some more, and then it was good.

The first lesson here is a reinforcement of Product Management 101: don’t necessarily do exactly what users ask for. Understand the motivating problem they’re trying to solve, and then solve that problem in the best way possible. As the developer, you know what’s possible more than your users do. Then, put those transistors to work! Don’t make your users do for themselves what you can do for them inside the software. Hide power behind simplicity, and it will not only be easier to use, it will be delightful. 

I’ve seen more than one unprompted grin from users testing out the new eraser. Penultimate is a great app, but there’s still potential for it to be greater. Stay tuned; we’re hard at work.

Ben Z.