Writing on Tablets Tech stuff from @yeltzland

App Development using Swift - A Summary

My first app written in Swift has now shipped and with the Apple Watch update now live too I think we can call it done.

So what did I learn?

Swift - good and bad

The Swift language itself is pretty well designed, and a LOT easier on the eye than Objective-C. The syntax is pretty similar to many modern languages and I think I became reasonably productive quite quickly.

The only downside is that most of the code I wrote was generally just interacting with the iOS frameworks, which aren’t particularly Swift-friendly right now. This means you spend a lot of time dealing with nullable pointers, and with all the slightly mysterious ?s, the code loses some of the readability gains.

Hopefully this will get better over time, any maybe this year’s WWDC will see some progress in making the frameworks a little more Swift-friendly? Let’s hope so.


I enjoyed using Swift, and almost certainly for any new apps starting from scratch I’ll use it.

However I don’t see there is enough - or any - real advantage in porting any existing Objective-C code so any existing apps that I’m working on I think I’ll keep that way.

Anyway, I learnt a lot and I hope you enjoyed following along!

Previous posts in the series

The code for the project is also available on GitHub

Apps Swift Count The Days Left

Pushing a WatchKit app to the AppStore

Now Count The Days Left is in the App Store, I thought I should push out the next WatchKit enabled version just in time for anyone who’s getting on on the first day.

Issues shipping a WatchKit app

The release process was pretty smooth - well as smooth as any release to the AppStore is - with a few extra steps needed because of the WatchKit support.

1. You need to add a new Watch icon and screenshots

Surprisingly the icon needs to be 1024px square, but I just reused the image I’d made for the main watch. The screenshots were easy enough to produce in the simulator.

iTunes Connect for WatchKit apps

2. No TestFlight support (yet?)

Bit of a pain this one - I suppose this may come later once the watch is out officially? Something to bear in mind if you want to test your app this way and have added WatchKit support.

3. All your version and build numbers must align

Another pain, as I was using a build script to auto-increment the build numbers for the main app - documented here. However there is no “Build Phases” section for the WatchKit App target in XCode, so I had to remove the script and manually set the build numbers to all match.

There are full details on the Apple developer site on preparing your WatchKit app for release.

Next steps

All done I think, just need to write a summary blog post in a day or so.

Previous posts in the series

The code for the project is also available on GitHub

Apps Swift Count The Days Left

Count The Days Left released

v1.0.0 is finally in the App Store!

It was the usual wait of about 8 days from submission until release, and I still can’t find it from my phone.

However if you really can’t wait, this link should take you there.

Next steps

I’ve released a new version (v1.0.1) including the WatchKit additions I made, hopefully in time for all those lucky people who are getting new Apple Watches.

There were a few things I had to do to ship the extension, and the steps needed requires a separate post.

Previous posts in the series

The code for the project is also available on GitHub

Apps Swift Count The Days Left

Playing With WatchKit

While v1.0.0 of “Count The Days Left” is waiting for review, I thought I’d have a play with getting a Apple Watch extension written for the app.

Simple is Good

Now as you probably know, the first version of WatchKit is very limited on what you can do in the UI. There are just a few standard controls, no way of writing your own, and any animation can only be done using image sets that are shown one after the other.

However the upside of this is it’s pretty quick to get up and running, and I’ve got something reasonable working after just an hour or so’s work.

Now there are lots of really good starter tutorials out there on getting up and running, so I’m not going to go into too much detail here, but here are a couple of articles I found particularly useful:

The thing that I thought was going to take the most time was generating the collection of images I needed for the animation of the progress circle. Fortunately I found a link to this Radial/Ring/Circle Progress Chart Generator for Apple WatchKit on GitHub which did exactly what I wanted!

Here’s a screenshot from the Watch Simulator with what the app looks like right now:

Count The Days Left on Apple Watch

I haven’t found a way of capturing the animation to show here as the progress circle moves into position, but on the simulator at least it works pretty well.

Next steps

Well I think I’m just about done!

I’ll probably write a summary article wrapping everything up once the app is safely released in the App Store.

Previous posts in the series

The code for the project is also available on GitHub

Apps Swift Count The Days Left

Waiting For Review

Version 1.0.0 of “Count The Days Left” is now waiting for review in the app store. Hurrah!

As usual it’s a bit of a slog preparing to ship the app, but it’s finally all done, which means hopefully it’ll be available for the public in a week or so.

App Store Video production

I wanted a preview video in the app store to show off the app’s gratuitous animation. This is now easy to capture as the latest versions of MacOS support having an iOS device as a video source for QuickTime.

However, it turns out QuickTime captures my iPhone 6 at nearly 60 frames per second, but teh App Store videos must be 30fps or less.

Luckily I found a nice utility program called Prism Video File Converter Free in the Mac App Store which did a nice job of the conversion, and I could add a short preview of the app.

I made a feeble attempt at adding a sensible description of what’s a pretty simple app, and now we’re all set to go.

Call for Beta Testers

Even though the app should be available in a few days, if you want to get a preview feel free to mail me and I’ll set you up in TestFlight.

Next steps

  • Hopefully a successful app launch
  • Start planning support for the Apple Watch using WatchKit

Previous posts in the series

The code for the project is also available on GitHub

Apps Swift Count The Days Left