Developer Spotlight: Lin Jinjie of PhocusTiPb's developer spotlights are like DVD/iTunes Extras for the App Store -- a weekly look behind the scenes at the programers and designers that bring you the iPhone, iPod touch, and iPad apps and games you love. This week Rene talks with Lin Junjie.

What's your name Lin Junjie. It's a Chinese name, so Lin is the last name and Junjie is my given name. Also happens to be exactly the same as a popular Chinese pop singer, so I get quite a number of wrongly directed tweets from his fan girls or people telling the whole world what song they're listening to.

What's your company's name? Phocus LLP, and its main business here in Singapore is photography (explained later).

Where are you based? I'm based in Singapore, a really tiny island on the equator where the only seasons are rainy or sunny.

What's your website address?

What's your Twitter ID? Company account at @dueapp, personal account at @jjlin

What apps do you make? Currently just one: Due for iPhone and iPad.

What apps, other than your own, are currently among your favorites? Carcassonne, Instapaper, Camera+, Simplenote, OmniFocus for iPad.

How long have you been a developer? I was very late to the party. I started developing only less than a year ago in July 2010. That was about a month after my graduation from communication school, and a year after I started my first business---a photography school based in Singapore.

I've always been a geek since my Dad bought our first PC in the 90s, but it was only in July 2010 that I decided to take time off my photography business to pursue my childhood interest of programming. So I started picking up Objective-C and embarked on my first project, a reminder app that eventually became known as Due.

What primary computer setup do you use for your iOS development? I'm using a 3.5-year-old MacBook Pro 15" non-unibody, propped up on a Rain mStand, hooked up to an external monitor and a Bluetooth keyboard most of the time. Most of Due was made while I was using a 22" Dell monitor on dual-monitor setup. I recently replaced the 22" with a Dell 30" and went with a single monitor setup instead. I find a large single monitor works a lot better with Xcode 4's single layout design than two smaller ones.

The other major thing I did recently was to replace my MBP's hard disk drive with an SSD, and now it feels like it could last me another 2 years before Apple could tempt me with their new notebooks.

(Photo of my desktop a year ago. Since then the 22" monitor has been replaced with a 30", and the iPhone 3GS with an iPhone 4.)

What iOS device(s) do you personally use most often? iPhone by a huge margin. For some reasons I still find myself uncomfortable to be whipping out an iPad during my commutes, even if I have both the iPhone and iPad with me.

While iPhones are everywhere here in Singapore, the iPads are relatively uncommon. Their large and super bright displays also attract a lot attention from curious strangers. So I tend to feel self-conscious when using it, almost like everyone is staring at what I'm doing (like right now I'm answering this in Simplenote on my iPhone rather than my iPad, even though I've both with me).

The other reason is that I tend to do quite a bit of writing during my commutes. In theory, the iPad with its near full-size keyboard should have been better suited for such tasks. In practice though it is way harder, if not impossible, to type if you commute by trains and buses and can't get a seat.

But other than that I really enjoy the experience of using an iPad and I feel like I should use it a lot more than I currently do.

What mobile devices, other than iOS, do you currently use? Only the iPhone and iPad.

What's your favorite thing about developing for iOS? My favorite part about developing for iOS is that anyone, even someone like me---completely new to the Mac/iOS development scene and without the advertising monies and distribution platforms of traditional publishers---can potentially make it big on the App Store as long as you make a great app.

It's almost like everyone is equal on the App Store. Well in practice I think Apple does pay more attention to apps from big name publishers or developers, and tend to feature them more, but it's about as good as a distribution platform can get for lone wolf developers like me.

For Due to sit alongside apps published by Apple, EA and get the same kind of exposure is not something I could dream of pre-App Store.

What's your least favorite thing about developing for iOS? Probably the wait for review and approval. Sometimes I could have shipped another update in the time it takes Apple to review and approve an update.

What feature would you most like Apple to add to the iOS 5 SDK? An overhaul of the notifications system that everyone is looking forward to. For me, whose app depends entirely on it, I'm really excited to see what Apple brings to the table, and what I could do with it for users of Due.

In addition to the qualms that most people have with the current system (too obtrusive, transient, etc), there are a few serious limitations at the moment that I'm hoping gets addressed. For instance, recurring local notifications are limited to every one second, minute, hour, day, week, and so on. This is the reason why the auto snooze function found within Due is limited to every minute and hour, and nothing in between. An auto snooze with finer intervals also happens to be the top support request I get, and I feel severely handicapped that it's not something within my control to fix until Apple improves the SDK on local notifications.

There are other things I look forward to, including better control of notification volume and vibration, as well as the length of sound alerts. This one is a long shot, but I also wish Apple could allow apps to run code with the tap of a button in the alert itself without launching the app to do so. In the context of Due, that would allow users to postpone a reminder, or to mark it as done, without launching into Due and interrupting whatever they were doing then.

What feature would you most like Apple to add to the App Store? To enable developers to respond to user reviews on the App Store. I'm greedy, so another one would be to see a list of apps that have been purchased before (and to download them again if they're not already installed), and to properly reflect them as a free download if a user were to download it again (I believe Apple is doing something on the iPad now, but the iPhone still doesn't reflect this correctly).

There are quite a number of occasions where customers have bought Due on their iPhone, and wish to have it on their iPad (or vice versa), but weren't sure if they would be charged again since they needed to tap on the $4.99 and 'Buy now' to download it again.

If we were to eavesdrop on you while you were coding, what curse word would we hear you use the most? I'm not sure, I think I'm the really quiet sort when working…

What do you do when you're not coding iOS apps? I photograph (it's a joint portfolio with my partner, so not all photos are mine) and teach photography, catch up on my Instapaper and RSS feeds, work out (Kettlebell, swimming and badminton lately).

What should we look for from you next? I'm planning for a Mac version of Due, but I'm finding it incredibly difficult to pull myself away from updating the iOS version because it is so close to me and I use it so frequently, I keep finding new ideas and ways to tweak it.

I also have plans for something other than Due, but seeing that I've yet to even sort out my time and resources with regard to the Mac/iOS versions of Due, I think I better not say anything at this point of time!

What's the best, funniest, or most creative use of Due you've heard about from a user? I don't think this one is considered funny or creative, but I find myself amazed that a number of people have close to 64 active reminders set up within Due at once. Sixty-four happens to be the maximum number of local notifications that an app could schedule under iOS, so very occasionally I get to hear about users who wish that they could add more. I don't know, but as much as I depend on Due, I think I would go crazy with 64 reminders beeping at me.

The other unexpected thing I learnt was how Due was helping users cope with ADD. Just recently Dave Caolo from 52 Tiger started a series of review on iPhone apps that help users cope with ADD.

I've also received a number of emails from users with ADD, and knowing that your app has made a positive impact on people's lives is truly gratifying. This is perhaps one of the biggest reasons why my heart lies with making productivity apps.

Thanks Jinjie!

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