How a simple scale app accidentally became a pet photo social network
Hi, it's Kei. The solo developer from Japan who keeps writing about her apps like they're her children. Because they kind of are.
If you've been following along, you know the story so far: I built apps, nobody used them, I cried about it on Medium, and then some very kind strangers on the internet gave me advice. I rebuilt all my screenshots. I kept going.
Today I want to tell you about the weirdest thing that's happened in my two years of indie development.
I built a pet weight tracker. I updated it obsessively for months. And somewhere along the way, it stopped being a weight tracker entirely.
The original idea was so simple
It started with my guinea pigs, Mochi and Kinako.
Guinea pigs are small animals. When they get sick, they hide it — it's a survival instinct. The first warning sign is usually weight loss. So the vet told me: weigh them regularly and track the changes.
I looked for an app that could do this. Couldn't find one I liked. So I built one.
The core concept was dead simple:
- Enter your pet's weight
- See a chart over time
- Export the data as CSV for your vet
That's it. That was the whole app.
Then I thought: guinea pig owners aren't the only ones who need this. Hamster owners weigh their hamsters. Bunny owners weigh their bunnies. Bird owners, ferret owners, chinchilla owners — they all track weight.
So I did what any reasonable developer would do.
I made nine separate apps.
Yes, nine apps
- Bunny Tracker
- Hamster Care
- Guinea Pig Care
- Ferret Care
- Chinchilla Care
- Bird Tracker
- Reptile Care
- Dog Tracker
- Cat Tracker
One for each animal type. Same core functionality, customized for each species — different weight ranges, different care guides, different emoji.
My friends thought I was crazy. "Just make one app with a dropdown menu for animal type," they said.
But here's the thing about pet people: they don't search for "pet weight tracker." They search for "hamster weight tracker" or "bunny health app." Having separate apps means better discoverability for each niche.
Also, I might be a little crazy. I won't rule it out.
And then nobody weighed their pets
I mean, some people did. The app worked perfectly for weight tracking. Beautiful charts, export functionality, multiple pet support — the whole package.
But when I looked at how people actually used the app, something interesting was happening.
People were using the photo diary feature way more than the weight tracking.
They'd open the app, skip past the weight entry, and go straight to adding photos with little notes. "Mochi looking sleepy today." "Max stole a treat from the kitchen." "Luna discovered the box."
I built a scale. They wanted a photo album.
So I leaned into it
This is the part where I could pretend I had some brilliant product vision. I didn't. I just listened to what users were doing and thought, "OK, you want photos? Let me give you photos."
Version 2.0 was a complete transformation.
I added a shared photo gallery — a community feature where all nine apps connect to the same cloud database. You post a photo in Bunny Tracker, and someone using Cat Tracker on the other side of the world can see it.
Let me say that again because it still blows my mind: a hamster owner in Germany can scroll through and react to a chinchilla photo posted by someone in Brazil. Through an app that was supposed to be a weight calculator.
Features I never planned to build
Here's what the "weight tracker" has now:
Five emoji reactions. Because a simple thumbs-up wasn't enough for pet photos. You can send a heart, a paw print, sparkles, and more. People use them constantly.
Species filter. A horizontal scroll bar at the top that lets you browse by animal type — or see everything at once. Want to look at just hamsters for 20 minutes? I respect that and I've built a button for it.
AI content moderation. Every photo goes through an AI check before it appears in the gallery. The AI verifies it's actually a photo of the right animal (no, you can't upload your lunch to Bunny Tracker), checks for inappropriate content, and makes sure nothing weird gets through. It's Claude, by the way — Anthropic's AI. It's surprisingly good at telling a hamster from a guinea pig.
Discord integration. Photos automatically post to a Discord channel when uploaded. I check it sometimes just to see what people are sharing.
Community backgrounds. You can set any photo from the gallery as your app's background. Someone's golden retriever is currently my Dog Tracker wallpaper and I'm not changing it.
A full care guide. Seven sections of health and care information for each animal, localized in multiple languages. Because if someone's using a pet health app, they probably want pet health information.
And yes, weight tracking is still there. It still works great. Beautiful charts, CSV export, all of it.
It's just not the main event anymore.
The numbers
In version 2.0, I had to build the entire photo system from scratch: CloudKit infrastructure, upload pipeline, image caching, hash-based duplicate prevention, reaction tracking...
In 2.1, I added interstitial ads with smart frequency control and Firebase Analytics.
In 2.2, I rewrote every App Store title and promotional text for all 9 apps across 35 languages. (My previous article about the 900 screenshots? That was 2.1. The rebranding was another round of "why do I do this to myself.")
In 2.3, I simplified the premium model. Made CSV export free for everyone. Premium just removes ads now.
In 2.4, more refinements. Stability. Edge cases.
In 2.5 — the version I just shipped — I added date pickers for weight entries, tappable record rows, and widget support preparation.
Six major updates in about two months. For nine apps simultaneously.
I'm tired.
What this taught me
Users will tell you what they want. Not with words — with behavior. I was so focused on building the perfect weight tracker that I almost missed the fact that people wanted a photo app. The data was right there. I just had to look at it.
"Pivot" sounds dramatic but sometimes it's just... leaning. I didn't throw away the weight tracking. I didn't rebuild from zero. I just shifted the emphasis. The weight feature is still there, still useful. But the photo gallery moved to the center, and everything else reorganized around it.
Niche apps can have community features. I know "pet photo social network" sounds ridiculous. But that's basically what it is now, and people genuinely engage with it. Small communities can be incredibly warm.
Maintaining nine apps is exactly as painful as it sounds. Every change gets multiplied by nine. Every bug fix. Every localization update. Every screenshot. I have scripts and templates and automated pipelines for almost everything now, but there's still a baseline cost that never goes away.
I'm still not making money. Let's be honest about that. The revenue from these apps is negligible. Most users are on the free tier, and the premium tier just removes ads. This is still a passion project, not a business.
But when I open the photo gallery and see a new chinchilla photo from someone I've never met, in a country I've never been to, reacted to by three other strangers who also love chinchillas — I don't know, that feels like it matters.
The before and after
What AnimalScale was (v1.0):
- A weight tracker
- Charts and CSV export
- Functional but boring
- "Please weigh your pet regularly"
What AnimalScale is now (v2.5):
- A pet photo diary with community features
- Weight tracking (still there, still good)
- Shared gallery across 9 animal types
- AI-moderated, reaction-enabled, multi-language
- "Look at this chinchilla mid-yawn and tell me you're not having a good day"
Same codebase. Same developer. Completely different app.
Please look at my pets
OK, I'll be honest about what I want.
I want more people to post photos of their pets. The gallery is alive and growing, but it's still small. Every new photo makes it a little better for everyone.
If you have any pet — literally any pet from a goldfish to a great dane — there might be an app for you. And if there isn't, well, my DMs are open for animal type suggestions. (Please don't suggest spiders. Please.)
All 9 apps are free. Find them here:
https://keik.co.jp/animal-scale/index-en.html
Post a photo. React to someone else's photo. Be part of the smallest, weirdest, most wholesome social network on the internet.
What's next
I have some ideas for the future. Widget support so you can see pet photos on your home screen. Maybe a "pet of the day" feature. Maybe expanding to more animal types.
But honestly? Right now I'm just going to ship v2.5, close Xcode, and go weigh my guinea pigs.
Some habits die hard.
— Kei
This is my third post. The first one was about nobody using my apps. The second was about rebuilding 900 screenshots. This one is about how a scale became a social network. I wonder what the next one will be about.
Probably something equally unhinged. Stay tuned.
