Writing on Tablets Tech stuff from @yeltzland

Objective-C or Swift for new projects?

If I'm starting a new iOS project, which language should I choose?

I’ve been crazy busy over the last few months - a good problem to have, but it means I’ve had no time to blog on here 🙁

I’ve been switching between loads of different technologies to build mobile apps during that time. I thought it might be interesting to share my experiences switching between Objective-C and Swift, and the pros and cons of each.


It’d been a while since I’d worked in Objective-C, but I took on a project for one of my clients to enhance and modernise a couple of their apps which hadn’t been touched in a while.

To be honest the original code was pretty awful - they’d been let down by some contractors in the past and it took me a while to get my head around how the app worked.

Objective-C is notorious ugly to look at, with all those square brackets in the method calling, but once you get used to it I find it pretty productive to use.

I think knowledge of iOS APIs is by far the most important thing when developing on iOS, not the particulars how to type the code to call the API methods required.

The biggest plus point for Objective-C is the speed and stability of Xcode and the compiler. After mostly doing Swift development in the last year or so, it was really nice to get fewer mysterious compiler problems.

I strongly suspect Apple still do most of their internal development using Objective-C, and until they move over wholesale to Swift there will be less internal pressure to improve Xcode to handle Swift more reliably.

The main downside was that more and more of the code examples out there on the web - especially for the more modern APIs - are now in Swift. Less opportunities for “Stack Overflow copy-and-paste” development 😊


Most of my own apps are written in Swift now, and I’ve been doing the usual summer updates to keep them up to date for iOS 11 - and this year also for the challenge of iPhone X and the notch.

I must admit I do like Swift, and in particular the way it forces you to think hard about nullability of objects. This enforced type safety can be a bit painful at times (all the “!” and “?”s) but I trulythink you end up with more reliable code in the end.

However, as I mentioned above, Xcode and the compiler are MUCH less reliable when using Swift. Quite often I’ve seen it do a poor job of recompiling changes, so you’re never 100% clear if you are seeing the latest code in the emulator. A restart of Xcode usually fixes it, but that’s a real productivity hit.

The Swift compiler is also feels noticeably slower than the Objective-C compiler. All those small delays soon add up.

Also Swift is still a bit of a moving target, and once again we have Swift 4 and changes to the language. These seem to be getting fewer over releases, but I really hope the language gets to some sort of stability soon.

So which language will I choose for new projects?

I think I’ll still choose Swift for any new projects when I have a choice. Apple have strongly signalled this is their preferred language going forward, and as a language I do prefer it to Objective-C.

However after a few months back using Objective-C, I’ve really enjoyed the stability and speed of the tools. Let’s hope the Swift tools can improve to a similar state soon.

iOS Swift Objective-C

Refreshing the Daily Optimiser UI

Daily Optimiser is the first iOS app I ever wrote, and it’s been looking a little tired and out of date recently.

So last week I spent a few hours improving and modernising the UI, and I’m quite pleased with the results (there are some screenshots are at the end of the article).

I’ve tried to be more consistent and subtle with the use of font size and color to give the information a clear hierarchy.

What was more interesting was how much I’ve learnt in the last few years of doing iOS development. Looking back at the original code, it’s clear I was I had no clear idea how best to structure the code. I was also very inexperienced in autolayout, and used tables EVERYWHERE to build screens!

I’ve also made the app iOS11 only to take advantage of large titles in the UI, but from my analytics I can see hardly anyone is using the app any more, so it’s not going to aggravate a non-existent user base.

I must admit I don’t actually use Daily Optimiser, as I prefer Todoist over Reminders as my task organiser. However if you are looking for a simple app based around Calendars and Reminders to help you organise your day, why not give it a go?

Download on the App Store

Screenshots of Daily Optimiser 4.0

Daily Optimiser 4 Tasks Daily Optimiser 4 Calendar Daily Optimiser 4 Add task

Apps Daily Optimiser iOS

Paying to remove ads

Why I added an option to remove ads in 'Count The Days Left'

Following on from an earlier post about why I put ads in my Count the Days Left app, I’ve now added an option to let users make an in-app purchase to remove those ads for a low, low price.

Why do this?

Two reasons really.

Clearly nobody likes ads, as they are very rarely relevant to what you are looking for. If you find them really irritating, you can now remove them.

Second reason is about money. It’s unlikely that I will earn £0.99 of ad revenue per user, especially as I’ve deliberately not put the ad in a prominent place for taste reasons. If users do pay to remove the ads, it’ll be (slightly!) more profitable for me.

This approach also gives users the chance to say thanks if they like the app. Asking for money while giving something back somehow seems a nicer approach than using a “tip jar” I’ve tried before.

Live long and prosper

I was particularly pleased with my use of the 🖖 emoji in the in-app purchase screen.

Screenshot of the Ad Free Screen

Feel free to contact me via Twitter at @yeltzland if you have any thoughts on any of this.

Count The Days Left Apps Swift

Thoughts on the future of iOS automation

Following Workflow's acquisition by Apple, my thoughts on where (I hope) they might be heading

As the whole iOS world knows, the excellent Workflow App was acquired by Apple last week.

IMHO Workflow is an essential part of using iOS productively, and I’ve already written a couple of times about how I use it.

I’m hoping the acquisition won’t going to turn out badly (although history shows it’s a real possibility), and I’ve been thinking about what Apple’s plans may be - quite possibly wishful thinking.

Current situation with x-callback-url

Many of the automation features in Workflow depend on apps implementing the x-callback-url specification. This method, which piggybacks on the iOS URL Scheme is an elegant hack to solve inter-app communication problems in a way that just aren’t possible using existing iOS extensions.

However, it’s unlikely Apple are happy with this as a long-term solution - in particular x-callback-url has no notion of security and can easily be abused.

Siri intents

Apple are already working towards allowing users to control apps without directly opening them up via Siri.

iOS 10 introduced Siri intents via SiriKit. This allows you to pass commands in pre-defined intents to apps that support them, and allow those apps to response in a structured way.

Clearly this is similar in usage to those functions exposed via x-callback-url.

Apple’s usual deliberate progress means Siri intents are only available in a limited number of domains right now (including VoIP calling, Messaging, Payments, Photos, Workouts, Ride booking).

I’d be shocked if this list isn’t greatly expanded in iOS 11. Hopefully we’ll find out more at WWDC 2017.

Some predictions

1. Workflows will be able to be triggered via Siri

This seems a no-brainer, and a great way of how the existing Workflow app could be greatly improved by being owned by Apple and having access to internal services.

Maybe even by iOS 11?

2. Apple will allow apps to add their own intents

This is definitely more speculative. Apple likes to tightly define what apps can and can’t do, so it feels too early for it to be opened up right now.

Also, for multi-language Siri support - something Apple does much better than Amazon right now - it’s clearly easier to support a smaller set of intents and gradually roll them out as the voice recognition models are trained.

However, if the intents were not just for voice, then there is less reason to restrict developers in this way. If an app could define its own intents for other apps to call them in a standard way, this could cause an explosion of automation opportunities.

I can’t see this happening in iOS 11, but would love to be proven wrong.

3. Workflow is transformed to be a “non-voice” way of calling intents

If apps could offer standard entry points as outlined above, then it would make sense that Workflow would switch to using them.

In fact if Workflow only supported calling intents (rather than x-callback-url entry points), that would be a strong incentive for app developers to switch to the “official” way of exposing entry points.

It also feels much more like an Apple way of doing automation.


I’m really hopeful the acquisition of Workflow was done to extend and improve iOS automation, rather than just an acqui-hire of the founders.

If my predictions are correct, I think we’d have a powerful system to allow our apps to be automated, and an extensible system to write secure and powerful scripts to tie apps together (that is integrated with Siri).

I’d be very happy - and shocked 😊 - if any of this comes true.

Feel free to contact me via Twitter at @yeltzland if you have any thoughts on any of this.

Workflow Siri iOS

Why I put ads in my app

Where I try to justify - mainly to myself - why it's OK to put ads in 'Count The Days Left'

I recently released a version of my Count the Days Left app which included ads for the first time.

I thought long and hard before doing this, so I thought it might be interesting to document how I worked through this decision, as it’s pretty typical of the trade-offs independent software developers have to make.

How I make money

I’ve been a commercial software developer for nearly 30 years now (wow!), including over 10 years working at Microsoft (MSN/Bing/Skype).

Right now, I split my time between:

  • Contracting out my skills to businesses for fixed-term projects
  • Building mobile apps and websites for businesses
  • Developing my own iOS and Android apps for both pleasure and profit

In 2017 I’m trying to diversify my business more, so the 3 areas above contribute more equally to the bottom line.

Currently, by far the biggest part of my income is working on contracts for other people, and I’m trying to generate more independent streams of income so I can be more in control of both my time and where I work.

Why I built Count The Days Left

I built the app for a few reasons, but mainly:

  • I wanted to showcase my skills to generate potential business
  • I wanted this app for myself, and most of the alternatives in the App Store were either ugly or not quite what I wanted

For the first point, I’ve blogged extensively about how I’ve built the app, as well as open sourcing the code on GitHub so potential customers can see my work.

The app has been pretty successful in meeting these aims, and has definitely helped in generating business (although it’s hard to measure the actual monetary value of this).

As you’d expect from a simple and niche app, it doesn’t have masses of users - daily users are definitely in the hundreds rather than the thousands.

In fact, some of the features (showing the days left as an icon badge, the Today widget, plus the Watch complication and app) are designed so the users don’t actually need to open the app every day, but I’m pretty proud of how it’s turned out.

Monitising the app

For any iOS app, there are three main ways of making money from an app:

  1. Charging to buy the app
  2. Adding an in-app purchase or subscription, probably to unlock additional functionality in an otherwise free app
  3. Adding ads

Now, unfortunately I suspect there is very little chance I’d sell many copies if I decided to charge for the app. There are so many free competitors to this particular app, and even if my app is better than them - and obvioiusly I think it is :) - it’s very hard to see how many customers would agree.

People are now so used to getting high-quality free software, generally from venture capital backed companies who are happy to lose lots of money to capture large audiences in the hope of monitising that audience later. That makes it a very hard sell to convince people even to spend $0.99 on an app that might provide them with lots of value.

Personally I’m happy to pay for good software, especially from independent software developers who are doing great work.

However I completely understand why most people don’t think in that way, and as I can’t see the situation ever changing, for most consumer apps I can’t see there’s much point in even charging a very small amount.

Now this particular app only really does one thing (although hopefully it does it well!), so I can’t see any sensible way of adding “pro features” to be unlocked by an in-app purchase.

I guess I could try a patronage/shareware model, and ask for money to support the app? I’m not sure that would actually generate any money without some sort of persistent nagging which I don’t think I’d be happy with.

This probably gets to the nub of my problem with all of this discussion. I’m not sure if it’s a British thing, but the conflict between needing to get paid and somehow seeming to be only doing it work the money is complicated.

I do want people appreciate and enjoy the app, and somehow this should be separate from the dirty business of getting paid.

So this just leaves adding ads.

Tasteful Ads?

I didn’t want the app’s main screen to show ads at any time. I think its’ main selling point is it’s a tasteful and good-looking app (especially compared to some of my competitors), and slapping an ad there would completely negate that.

Therefore only other place left to put the ads is on the settings page, where you change the title, start and end dates of what you’re counting down to.

I’m reasonably happy with this compromise, although from a pure money-making point of view this page is not viewed very often, as the users only go thereevery time they start a new countdown.

I’m using Google to provide the ads via AdMob, and have customised them to be text-only and in a color that matches the rest of the app. At least in that way they are not too jarring, and fit in as well as I can make them.

As you can see from this example, the way the ad looks is OK (even though the content is frankly a bit shit)

Screenshot of the Ad

Is it worth it?

In the first week, I’ve made a few pennies - slight more than I expected, which was very little be honest!

However, I’m generally happy I’ve done this. I think it’s important all software developers get paid fairly for their work, so turning the tide against the idea all software should be free - even the the smallest way - is OK.


Obviously giving Google even more data is not “free” for my customers, as they are now paying for the app with their information. I’m not 100% happy doing that, but as I’ve hopefully explained here, it’s a complicated trade-off.

Feel free to contact me via Twitter at @yeltzland if you have any thoughts on any of this.

Update (2017-04-11)

I’ve now added an option to pay to remove the ads - read about it here

Count The Days Left Apps Swift