Why a Sparrow for iOS app now? Have Apple's policies changed, is iOS email simply in need of improvement, or something else?

We don't know about Apple policies yet but since they accepted Gmail and other Mail applications, we figured we should go for it. We're confident that Apple will accept Sparrow. They did it on the Mac App Store. It won't make any sense to reject us on their mobile platform. We'll know in a few weeks anyway.

What phone do you use?

An iPhone 4S.

How much emailing do you do on a given day?

50-70 mails max per day. That's certainly above the average but I am not a crazy mailer.

When you've got hours of coding to do, what are your go to music choices?

I don't code. I wish I was but I don't. 3 songs that I have been listening a lot lately:

• Get By - Modern Borders
• Why so Serious? - Hans Zimmer & James Newton Howard
• Rej (Original Mix) - Ame

Since I use Spotify, I generally pick a random playlist and switch into discovery mode.

What is your first memory of the internet?

I was 13 and just got a first gen iMac. I created my first mail account and sent a mail to my school '@info' address complaining that our principal was frequently unavailable. It turned out the mail ended up directly in the principal's mailbox and that he was really sick. After an appointment with my parents in his office, I was excluded for a week. A pretty good start.

Email is declared dead a few times a year. Why the staying power? Does it need to evolve?

How did you apply for your job? How do you negotiate a deal? How do you review your employee work? What tool are you using when you're sending message to your loved ones? SMS, Facebook messages, What's app, Kik are all great new means of communication but mail still has its own territory. Email definitely needs to evolve. Sparrow 1.x is an attempt to marginally change habits.

Mail did not evolve for a long time and didn't integrate with the cool new tools that were created in the last 5 years. We're doing our best in Sparrow to integrate services that people are using outside mail like DropBox or CloudApp. Facebook Connect was also pretty important to us. People's faces matters a lot both on an emotional level and on a UX level, as visual cues.

We are trying to make the experience simpler and more enjoyable. This is the first step. Now that we have a pretty solid technical basis, we want to move on a 2.0 version where we can change the paradigm of mail: the way people think of it and use it.

What's the history behind Sparrow's beginnings? Why another mail app?

My partner, Hoa Dinh Viet, and myself both worked 2 years in a iPhone/iPad development company. When we left, he told me he had been working on a mail engine for several years and wanted me to work on UI/UX design for it. Both of us were not satisfied with existing mail applications on the Mac so we figured we could give it a try.

We launched the first beta in October 2010. The feedback was amazing with more than 70 000 downloads in the first week. We both left our day jobs and Sparrow was funded and incorporated 2 weeks later. Jean-Marc Denis joined the team a few weeks later as our designer.

What's the give and take between adhering to popular OS X UI conventions and going in your own direction?

I think there is a huge variety of design on OS X but the 2 main choices that a developer / designer really has are the orthodox way, sticking with the Apple HIG in a strict manner, or the Loren Brichter's way.

I am not saying that there is no in-between. A lot of our inspiration in Sparrow comes from other developers who are not strictly following the HIG or Loren's UI style. But like on the iPhone with the pull to refresh or the cell swipe, Loren created a new standard with its Tweetie core animation sidebar.

I am not a technical person, but it seems that both ways have their advantages. One allow you to be sure your app will be simple to understand, the other lets you try new things that might get the user lost.

What should Google have done to improve the Gmail for iOS app?

Make it native. It makes no sense (yet) in the iOS ecosystem to provide a web app, especially for mail where you want it to be fast and responsive. I am convinced that there will come a time when the web will take over and no one will be able to tell the difference between a web app and a native one but we're not there yet. Today and for a few years, native apps will still provide a better experience.

What's your favorite Mac app? Windows app?

The very first release of Twitter a.k.a Tweetie 2 for Mac was epic.

Right now, iA Writer is my favorite and most used Mac App. Pure and inspiring are the two words that comes to mind each time I open it. Oliver Reichenstein is setting the bar pretty high for developers on the Mac. Sometimes I just open the app and type anything, just to play around. Spotify for Mac is also pretty impressive in terms of efficiency and reliability.

Concerning Windows, I haven't touched a PC since almost 10 years. I am sure there are some interesting stuff there but I just don't have any PC around to play with.

The Mac App Store has been huge for you, what are some of the tradeoffs? Where can Apple improve?

80% of our traffic comes from the MAS. It works.

The only weak points are updates and bug fix. Waiting 4-5 days + development time to get a annoying bug fixed for your users is still too long. Apple provides some shortcuts like the 'Expedited Review' but it does not work every time and there is still a delay between the time you're ready to ship and the time your users can get it.

Concerning update notification, we put a lot of effort in improving Sparrow and we feel the Update section of the MAS is not an appropriate way to channel the notification to the user. Users have to open the MAS app, go to the update section and click the 'Update' button. This works well on the iPhone because it was a new ecosystem creating new habits but on the Mac, it feels cumbersome.

Last detail: Apple should create an Apple application category and remove its apps from the main ranking. 7 of the top 10 paid apps are made by Apple which leaves 3 slots to indie developers.

What are your top designed mobile apps?

Path 2.0 is the most beautiful app I have seen in a long time. It has become my most used app by far. Twittelator Neue is beautiful too. I think people underestimate the effort and care that has been put into this application. There's a lot of really cool ideas and animations there. I like Flipboard too because it's surprisingly fast and elegant in a minimalistic way.

What books are you reading now?

The Icon Handbook by Jon Hicks and The Tipping Point by Malcolm Gladwell.

Print or ebook?

Ebook. Sparrow is based in Paris so it's hard, or at least complicated, to get new US printed versions on the day of their release. I always buy both the eBook and the print version and usually read my favorite parts a second time when the print gets delivered.

What are your favorite design books?

Designing Visual Interfaces: Communication Oriented Techniques by Kevin Mullet and Darrell Sano is the book I keep going back to.

I think the best way to learn UI / UX design is to spend a few days looking at the UI of a specific application and try to understand the choices that were made. I don't mean standing behind your desk and playing with it, I mean actually trying to understand the design decisions step by step. In an app like Tweetie / Twitter for iPhone, this is pretty intense. Reverse-engineering the UI is not easy but helps generate ideas and identify what could not have worked. To give another recent example, it's very hard to do this on Path 2.0. The end result of the design process is so simple and straightforward that you can't really find a starting point. Usually, starting points are the weird design or weird interactions of an app. From the weak point, you can navigate to a first design decision, then a second one and so on.

Blogs are my main resources for design: Daringfireball.net - Ignorethecode.net/blog/ - Beautifulpixels.net - Dribbble.com - Creativeapplications.net - Butdoesitfloat.com

Most of the inspiring stuff I see comes from websites unrelated to UI / UX.

How much of an inspiration was Tweetie in your designing of Sparrow? What about Twitter works for email?

We got in touch with Loren at the very beginning of Sparrow's development. The Tweetie / Twitter sidebar was the best design I had seen for quite a while on the Mac. It was the nicest way to switch between accounts. We asked him if we could borrow his design for Sparrow and he was kind enough to let us take it.