Structure and Interpretation of Computer Programmers

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Thursday, August 27, 2009

Indie app milestones part one

In the precious and scarce spare time I have around my regular contracting endeavours, I’ve been working on my first indie app. It reached an important stage in development today; the first time where I could show somebody who doesn’t know what I’m up to the UI and they instinctively knew what the app was for. That’s not to say that the app is all shiny and delicious; it’s entirely fabricated from standard controls. Standard controls I (personally) don’t mind so much. However the GUI will need quite a bit more work before the app is at its most intuitive and before I post any teaser screenshots. Still, let’s see how I got here.

The app is very much a “scratching my own itch” endeavour. I tooled around with a few ideas for apps while sat in a coffee shop, but one of them jumped out as something I’d use frequently. If I’ll use it, then hopefully somebody else will!

So I know what this app is, but what does it do? Something I’d bumped into before in software engineering was the concept of a User Story: a testable, brief description of something which will add value to the app. I broke out the index cards and wrote a single sentence on each, describing something the user will be able to do once the user story is added to the app. I’ve got no idea whether I have been complete, exhaustive or accurate in defining these user stories. If I need to change, add or remove any user stories I can easily do that when I decide that it’s necessary. I don’t need to know now a complete roadmap of the application for the next five years.

As an aside, people working on larger teams than my one-man affair may need to estimate how much effort will be needed on their projects and track progress against their estimates. User stories are great for this, because each is small enough to make real progress on in short time, each represents a discrete and (preferably) independent useful addition to the app and so the app is ready to ship any time an integer number of these user stories is complete on a branch. All of this means that it shouldn’t be too hard to get the estimate for a user story roughly correct (unlike big up-front planning, which I don’t think I’ve ever seen succeed), that previous complete user stories can help improve estimates on future stories and that even an error of +/- a few stories means you’ve got something of value to give to the customer.

So, back with me, and I’ve written down an important number of user stories; the number I thought of before I gave up :-). If there are any more they obviously don’t jump out at me as a potential user, so I should find them when other people start looking at the app or as I continue using/testing the thing. I eventually came up with 17 user stories, of which 3 are not directly related to the goal of the app (“the user can purchase the app” being one of them). That’s a lot of user stories!

If anything it’s too many stories. If I developed all of those before I shipped, then I’d spend lots of time on niche features before even finding out how useful the real world finds the basic things. I split the stories into two piles; the ones which are absolutely necessary for a preview release, and the ones which can come later. I don’t yet care how late “later” is; they could be in 1.0, a point release or a paid upgrade. As I haven’t even got to the first beta yet that’s immaterial, I just know that they don’t need to be now. There are four stories that do need to be now.

So, I’ve started implementing these stories. For the first one I went to a small whiteboard and sketched UI mock-ups. In fact, I came up with four. I then set about finding out whether other apps have similar UI and how they’ve presented it, to choose one of these mock-ups. Following advice from the world according to Gemmell I took photos of the whiteboard at each important stage to act as a design log – I’m also keeping screenshots of the app as I go. Then it’s over to Xcode!

So a few iterations of whiteboard/Interface Builder/Xcode later and I have two of my four “must-have” stories completed, and already somebody who has seen the app knows what it’s about. With any luck (and the next time I snatch any spare time) it won’t take long to have the four stories complete, at which point I can start the private beta to find out where to go next. Oh, and what is the app? I’ll tell you soon…

posted by Graham Lee at 00:44  

Monday, August 17, 2009

On XP mode

This is a reply to @gcluley, who linked to this ZDNet story (which in turn took its quotes from Sophos Podcasts).

The second most crazy thing about the entire “XP mode” issue in Windows 7 is that the feature is entirely unnecessary. Corporate customers of Windows are already, for the most part, comfortable with managing virtual Windows desktops through third-party products with much better management options or at least have trialled such products. Home users of Windows just take whichever version is pre-installed when they buy the PC and if it means buying new versions of some apps, that’s what they do. They’re used to it. The group of people who could benefit from XP mode – people with a strong need for app compatibility with XP but with no experience of virtualisation – just doesn’t exist.

The very existence of the XP mode feature is a microcosmic example of the way Ballmer has been running Microsoft – if there’s a market out there that MS isn’t in, MS needs to be in it pronto. Bing, Morro, Web-Office, Zune and now virtualisation are all testament to the inability of Microsoft to concentrate on what it does. What Microsoft really does is to sell two things; an enterprise computing environment and an OEM software distribution. Forget that Windows and Office are accounted as two separate products; MS sell Windows+Office to businesses and Windows to computer makers.

Now the interesting question to ponder is which of Microsoft’s (real or perceived; remember they aren’t necessarily in this market) competitors the “XP mode” feature is a response to. My interpretation is that it’s not actually VMware and its ilk at all – Microsoft is once again responding to nonexistent competition from Apple. Boot Camp and the third-party desktop virtualisation offerings on the Mac (including, without hint of irony, VMware) let users use OS X as their shiny new OS with an “XP mode” of sorts for legacy applications. I think what Microsoft are trying to do here is to show that Windows can be the new shiny with XP as the legacy mode, and are therefore positioning XP mode as a counter to the fictitious competition from Apple. Oh, and if you don’t believe me when I say that the competition from Apple doesn’t exist – Apple sell all of the premium computers while Microsoft take the aforementioned corporate and OEM markets.

OK, so if that was the second most crazy thing about XP mode, what is the most crazy thing about XP mode? It’s also that the feature shouldn’t exist. Windows has always had a problem with segregating distinct services which other operating systems don’t suffer from. While Microsoft’s avoidance of this issue has allowed a whole new software industry to spring up around it, the fact that they need to start a second copy of Windows just to get some applications running in Windows 7 doesn’t give me much hope for the future.

posted by Graham Lee at 23:54  

Friday, August 14, 2009

The next million-dollar iPhone application

I’m constantly surprised by questions such as this one. They invariably go along the lines:

I heard that I need to get a Mac to do iPhone development. I want to do iPhone development but do I have to buy a Mac? Is there any other way to develop iPhone software?

If the projected sales for your app don’t meet the cost of a new computer, whatever platform you’re developing on, it’s time to get a different idea for your app. I speak with the smug self-confidence of one who has yet to get his own app within smelling distance of the store.

posted by Graham Lee at 18:53  

Thursday, August 13, 2009

A rap upon the noggin

When a patient may be concussed, it’s common for parademics to ask simple, topical questions to determine whether the patient is confused. Questions such as “who is the Prime Minister”?

I think somebody may have knocked this poor spammer upside the head (emphasis is mine):

Lloyd’s TSB Group plc
25 Gresham Street
London EC2V 7HN


Following the recent announcement by the Chancellor of the Exchequer, Gordon Brown that all assets in accounts that have been

dormant for over 15years be transferred to the Treasury i send this mail to you.

There is a dormant account in my office,with no owner or beneficiaries. It will be in my interest to transfer this assets

worth 20,000,000 British pounds to an offshore country. If you can be a collaborator/partner to this please indicate interest

immediately for us to proceed.

Remember this is absolutely confidential,as i am seeking your assistance to act as the beneficiary of the account, since we

are not allowed to operate a foreign accounts. Your contact phone numbers and name will be necessary for this effect.
I have reposed my confidence in you and hope that you will not disappoint me.

My Regards,
Jim McConville
Lloyd’s TSB Group plc

posted by Graham Lee at 09:20  

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