I was 40kg heavier, staring at a paywall for a line chart. That’s when I realized: the fitness industry had turned my own body into a subscription. Every month, I paid for the privilege of seeing my own progress—and the data lived on their servers, not mine.
So I quit. Not the gym—the apps. And I built my own.
Meet Kilo: an open-source, local-first workout, weight, and calorie tracker that stores everything on your phone in SQLite. No account. No cloud. No paywalls. Just your data, your rules.
If you’re paying $10/month to see your own data visualized, you’re not a customer. You’re a tenant. And that’s the paradox of digital fitness: we’re chasing a basic human need—physical health—through tools that treat us like renters. Every rep, every meal, every pound logged is locked into someone else’s database. Want to export? Good luck. Want to visualize trends? Pay up. Want to switch apps? Start over.
Kilo flips that. I built it because I lost 40kg by logging everything manually—calories, lifts, weight—and got tired of writing custom scripts just to see a simple trend line. The apps that do it well, like Strong or Hevy, are heavily paywalled. Every useful feature costs extra. So I scratched my own itch.
Now, after a month of using it myself, I’m releasing it to the world. It’s free, open-source, and requires no account. It gives you deep analytics: lift progress, body heatmaps, personal records, estimated 1RM, tonnage per muscle group, date-filtered sets—everything you need for progressive overload. And if you’re coming from Strong or Hevy, you can import your CSV history. No data loss. No vendor lock-in.
The most valuable health data is the data you own, not the data stored on a server. That’s not a feature—it’s a philosophy. And it’s the reason Kilo exists.
I’ve seen this pattern before. Great products start when someone solves their own problem. But the fitness industry has convinced us that we need their cloud, their algorithms, their monthly fee to get stronger. It’s a lie. The only thing you need is a log, a plan, and the discipline to show up. Kilo gives you the log—without the bill.
You can install it via APK from GitHub Releases, or add the repo to Obtainium for auto-updates. It’s not on F-Droid yet (I’m still working out the self-updater policy), but that’s coming. Drop feedback, issues, or feature requests on GitHub. I’m actively developing it.
And if you’re still using a paywalled app, ask yourself: Why are you renting your own progress? The answer might just be the push you need to switch.
FAQ
Q: Isn't a local-only app inconvenient? What about syncing across devices?
A: It's a trade-off. You get full privacy and zero subscription fees. For now, you can manually backup the SQLite database file. If you're tech-savvy, you can sync it via file sharing tools. The app is designed for single-device use, but future updates may add optional sync. The point is: you control the data.
Q: What's the practical implication for me? Should I switch from my current app?
A: If you're tired of paying for features that should be basic—like viewing your own progress over time—then yes. Kilo is free, open-source, and gives you analytics that even paid apps charge extra for. You can import your history from Strong or Hevy, so you don't lose anything. The only thing you lose is the monthly bill.
Q: Isn't the cloud better for analytics and AI coaching?
A: Not if you value privacy. The best analytics are the ones you control. Cloud-based apps can sell your data, change terms, or shut down. Local-first doesn't prevent you from using AI—you can run models locally or use open-source tools. The key is that you own the raw data, not a company. That's a foundation you can build on for decades.