The cost of building software that does not want anything from you

This week I shipped OS 27 updates for all six of my apps: Book Tracker, Movie Tracker, Music Tracker, Game Tracker, Habit Tracker and Countdown Widget. They track different things, but they are built by the same person and they follow the same rules.

A lot of tracking apps came out this year, and more will come in the next few months. I am not going to tell you they are bad, because I have not used most of them and some of them are probably very good. But I have been shipping these since 2019, and this seems like a reasonable moment to write down what they all have in common, and what it costs me to keep them that way.

Someone wrote this

Every line of these apps was written by a person who knows what it does.

That sentence would have been meaningless in 2019. It is not meaningless now.

Here is what it buys you in practice. When you write to support and tell me something is broken, the reply comes from the person who wrote the code that broke. I do not have to work out what that part of the app was supposed to be doing before I can fix it, because there is no corner of these codebases that nobody understands anymore.

That is what decides whether an app survives. Code you do not understand is code you cannot maintain, and an app you cannot maintain gets abandoned, usually around the second or third year, usually quietly. The App Store has no shortage of tracking apps that stopped getting updates a year or two in.

Six apps updated on the first day of OS 27, by one person. You can check that yourself, the release histories are public.

The three years I did not add AI

Since 2023 I could have put a chatbot in any of these apps without much effort. Summarize this book. Recommend what to watch next. Write the review for me. It is one API call, and every one of those calls would have taken something out of your library and sent it to a server that belongs to someone else.

I did not do it. Not because I think the technology is worthless, but because I made a promise in 2019 about where your data lives, and none of the available ways of doing it kept that promise.

So I waited. For three years, while it would have been easy and while it would have helped every listing, I shipped no AI features at all. You can verify that too. It is in the release notes.

This week's updates are the first with any AI in them, and there are only two kinds.

Tag and genre suggestions, in all six apps, which run on your device. When you tag a book or an album or a game, the app proposes tags you already use. Nothing is applied on its own and nothing leaves the phone.

And a written recap of your year, in Book Tracker, Movie Tracker, Game Tracker and Habit Tracker. That one uses Private Cloud Compute, because writing a few paragraphs about a year of reading or watching needs a model too large to run on an iPhone.

I want to be precise about that second one, because precision is the whole point of this piece. Private Cloud Compute is the only infrastructure of its kind where the data sent for processing is never stored, is never used to train a model, and cannot be read by the company running the servers. The server code is published for independent researchers to inspect. It is the only version of this that I was willing to ship.

Music Tracker and Countdown Widget have no recap, so nothing in them goes anywhere at all. I did not add one for the sake of having the feature.

And in every app there is a switch in Settings that turns all of it off. If you never want any of this, you will not have it.

You can always just buy it, and what that costs me

Book Tracker and Countdown Widget are a single purchase and nothing else. The other four offer a subscription as well, and I would rather tell you that here than have you find it on the App Store page.

What I hold to is this. In all six apps, buying it once and keeping it forever is always available. It is never hidden below the monthly plan, it is never the worse version, and nothing you have already paid for gets moved behind a subscription later. Someone who bought Book Tracker in 2019 has paid me nothing since and is running this week's update today. If you never want a recurring charge from me, you never have to have one.

That is not a small distinction, and it is the one that shapes everything else here. When a large share of the people using an app have paid once and will never renew anything, designing the app around renewals makes no sense. There is no reason to invent a streak, or a notification that asks where you have been, or a badge for going faster, because none of it would be keeping anyone.

The subscription exists for two kinds of people. Some cannot spend the full price today, and a few euros a month is the difference between using the app and not using it. Others have told me they want to keep supporting the work after they have already paid once, and a recurring option is the only way I can let them. Neither of those is a reason to push anyone towards it, which is why the one time purchase sits right next to it, at the same level, showing the same features.

I should also be honest about the cost, because the version of this argument where the developer is purely virtuous is not true. A model built on subscriptions alone would earn me considerably more. Letting people buy once means I make less and I move slower. Some things take longer to build than they would otherwise, and I have said no to things I wanted. That is the actual trade, and I would rather tell you about it than pretend there isn't one.

Nothing to sign up for, nothing to escape from

There is no account in any of these apps. You do not create one, you do not give me an email address, there is no password of yours for me to eventually lose in a breach.

Your data lives on your device and in your own iCloud account, encrypted. I cannot see it. Nobody I work with can see it, because I do not work with anybody in that sense. There is no analytics provider, no advertising identifier, no third party SDK quietly counting things.

And you can take all of it with you, which matters more than it sounds.

The backup is the complete version. It exports as a zip with a JSON file inside it that reconstructs your entire database: everything the app holds about your library, not a selection of it. That file is yours, it is readable, and you do not need me or the app to open it.

CSV is the practical middle ground for moving between apps, but it is a table, so it holds what fits in columns and not everything the app knows. PDF is a document to read or keep, not a way to move your data. I am saying this plainly because plenty of apps call a partial CSV an export and leave it there.

This week's updates also rebuilt import from scratch in Book Tracker, Movie Tracker, Music Tracker and Game Tracker, so if you are coming from somewhere else you can bring everything with you and see exactly what will happen to your library, row by row, before anything is written.

Both directions, deliberately. You should be able to walk out with your data whenever you like, without asking me for permission and without waiting for me to process a request. An app that is hard to leave is not loyal, it is just locked.

They do not want your attention

None of these apps sends you notifications to come back. There are no badges for going faster, no leaderboards, nothing designed to make you feel behind.

Habit Tracker has streaks, and I want to be clear about why. In an app for habits the streak is the data, it is the thing you asked to measure, and hiding it would make the app useless. What it never does is use it against you. There is no notification warning you that a streak is about to break, no pressure to protect one, no penalty when it ends. It is a number you can look at, not something the app holds over you.

The rest is the same across all six. You open the app when you finish a book, or want to write down a line you liked, or want to log a session. Then you close it and go back to the thing itself, which is the actual point.

Built by someone who uses them

The last rule is simple, and it is where most of the design decisions came from. I read, I watch films, I collect records, I play games, and I keep countdowns for things I am looking forward to. Every one of these apps started because I wanted it, and most of what has been added since came from someone writing to me with a request.

The short version

I have written all of this down permanently, and updated it this week: https://booktrack.app/the-book-tracker-manifesto/

If you use any of these apps, thank you. Seven years is a long time and it has only worked because people kept writing to me.

Simone