Michael Simmons is co-founder of Flexibits, the company behind our favorite calendaring app for Mac, Fantastical. In building Fantastical, he has become something of a mentor to the app community, embodying simple yet effective design principles. Simmons took a few minutes to talk to The Verge about about building a calendar that understands your words, skeuomorphism, and when / if / how iOS and OS X will converge down the road. You can find him on Twitter here, and find Fantastical half-off for the rest of the summer here.

Where are you? What have you done so far today?

I'm in the Bay Area. So far today, I woke up, replied to all of my morning emails, helped answer our current support tickets, and now I'm doing this interview.

There aren't very many standalone calendar apps for Mac, yet calendar apps are something people use every day. Why aren't more developers in the game?

I think it's because it's a big problem to solve. There were so many details we become aware of as we started making Fantastical that almost made us say "forget it, this is going to be too much." So, it's a real commitment to make a calendar app once you get going. Features like alarms, attendees, delegated calendars, all the services, repeating events — I could go on and on...

"You have to take the basic notion of a calendar and make it better."

Why did you choose to stick Fantastical in the menu bar? Lots of people rely on "month view" with data in each day box.

Our goal was always to make Fantastical an app you quickly open, do your task(s), and quickly have it get out of your way. Making Fantastical a menu bar app seemed like the way to go.

While people insult iCal's skeuomorphic UI elements, they often forget that iCal (and Fantastical) are skeuomorphic in another way: they both use an "old school" calendar grid. What should a calendar look like? Why do you show us the past?

I think the kinds of skeuomorphism that are annoying are the ones that are done for no beneficial reason. For example, iCal uses a brown leather with stitching at the top and "torn paper shreds" that are distracting. A calendar should look like a calendar to make it friendly and familiar, but you have to take the basic notion of a calendar and make it better.

How do you like selling Fantastical in the Mac App Store? Is giving Apple a 30% cut of your sales worth whatever publicity being in the Store gets you?

It's been great for us. Apple really does give us our money's worth in terms of having a venue that has lots of customers, the ability to easily upload our app and while some developers complain, the approval process is like a second QA test phase that actually has caught bugs we've missed in the past. We still have our own direct store (which does well enough for us to keep), but the majority of our sales goes through the Mac App Store and we've been very pleased with the support and response from Apple.

"The key to making a great app, is having frictionless software that truly helps the user."

Fantastical is built around an incredible language parsing engine. What was the biggest challenge in building and implementing it?

Making it work for "everyone." With natural language parsing, just like in real life, when you speak with another person, it's never going to be 100%. Even people mishear or misinterpret what the other person said. So, you have to do the best job you can. Try to come up with the most likely scenarios or ones that, if they fail, fail gracefully. The key to making a great app, is having frictionless software that truly helps the user and truly improves their life.

I heard you speak a couple weeks ago in San Francisco where you said that people will pay premium prices for great apps. How did you decide on $20 for Fantastical? Do you think that price point scares a lot of people off?

Pricing is a very complex topic and varies greatly per product, but with regard to Fantastical, $20 was a price we discussed and researched quite a bit. We decided on this price since other "full" calendar/productivity apps were about $40-$50, so we wanted to make Fantastical a price that wouldn't convey that it was a "full" app. But we also didn't want to make it $10 and make it seem like it is something super simple or cheap.

An app like Fantastical requires quite a bit of support (with many different calendar servers, event types, etc.) so believe this or not, we sort of want to scare off the potential users who don't value our work. There's definitely truth in the price of customer acquisition and the costs involved. That said, we think $20 for an app that we've, so far, provided over a year's worth of free updates is a very good deal.

"OS X will remain different: more utilitarian."

Are OS X and iOS going to truly converge at some point, or will they always be somewhat separate? Where do you see Macs a few years down the road?

I believe they are converging now but they will always remain different. iOS devices are consumer computing devices and Macs are personal computers. I agree with what Steve Jobs had said, how personal computers are like trucks and consumer computing devices are like cars. Macs are the tools to create technology. I also believe many more iOS innovations will come to OS X which will help the experience. Still, OS X will remain different: more utilitarian.

What technology in the market today is most exciting to you? Where will it be in 3 years?

Voice recognition, aka Siri. I hope, in 3 years, it will be to the point where it learns what you want even if it gets it wrong. So it can adapt to the user's desires and help make tasks even easier. If you notice, we're moving away from keyboard and going to touch and now, voice.

What past technologies have inspired your work the most?

Everything from Apple. It might sound cliché or fanboy-esque, but Apple products reinvent, rethink, and reimagine. It's incredibly inspiring to see the love, passion, and care that goes into their products. It's something we at Flexibits strive for every day.

"That's one of the biggest traps — doing things on automatic mode."

What's the best book you've read lately? How has it impacted you?

Predictably Irrational by Dan Ariely. It made me aware of the fact that there are many things we believe are true that might actually be incredibly wrong. We get stuck in incorrect paths that are actually counterproductive, even though they "feel" proper. So, I now try my best to question everything I do, even if I "feel" like it's the right thing. That's one of the biggest traps — doing things on automatic mode, so I encourage everyone to rethink everything on a daily basis.

What apps (on desktop and mobile) are most important to your day-to-day workflow?

Safari, Mail, iChat, Tweetbot, Kickoff, Yojimbo, and, of course, Fantastical.

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