Cardia — Terms
These are the terms for using Cardia, an iOS app I make under the name Koirala Studio. Read these once and you'll know what you're agreeing to. If anything's unclear, email support@koirala.studio and ask.
Using the app
You can use Cardia on any Apple device you own, for personal stuff. Don't try to reverse-engineer it, don't resell it, and don't use it to break the law or hurt anyone.
Subscriptions
Cardia Premium unlocks full access after your early estimated fitness age reveal — ongoing resting HR and HRR checks, stable baseline estimates, the home gauge, daily check-ins, goal planning, journey tracking, full reading history, estimate trends, PDF export, and optional reminders. Free users get two checks total (one resting, one recovery) to reach that early reveal; a subscription is required to continue. Cardia Premium is offered as an auto-renewing subscription at $7.99/month or $19.99/year. Current prices are also shown in the app at purchase.
The Apple-required fine print on auto-renewals:
- Payment is charged to your Apple ID at confirmation of purchase.
- The subscription renews automatically unless you turn off auto-renew at least 24 hours before the period ends.
- Your Apple ID is charged for renewal within 24 hours before the current period ends, at the rate of the plan you picked.
- To cancel: Settings → [your name] → Subscriptions → tap the app → Cancel. You can also reach this from inside Cardia under Settings → Premium → Manage subscription.
- If you cancel mid-trial, any unused trial time is forfeited.
- Prices are shown in the app at purchase, taxes included where required.
Refunds
Apple handles all payments and all refunds. I can't issue them myself. Go to reportaproblem.apple.com within Apple's refund window; Apple decides.
Not a medical device
Cardia estimates a wellness-oriented "fitness age" from resting heart rate and heart rate recovery readings taken with your iPhone camera. Those readings can vary with stress, caffeine, sleep, temperature, how still you are, and how you perform the effort step — and the estimate can be wrong even when the capture succeeds. Cardia is for tracking trends and building habits over time, not for diagnosing conditions, detecting emergencies, or replacing a doctor, cardiologist, or any clinical test.
Don't use Cardia to decide whether you're having a medical emergency. If you feel chest pain, severe shortness of breath, fainting, or anything that worries you, call emergency services or seek medical care — don't wait for an app reading.
Cardia is not a medical device. It doesn't diagnose, treat, or prevent anything. If you have a medical concern, talk to a healthcare provider, not an iPhone app.
Use it sensibly
Take readings when you're safe to pause and follow the in-app instructions — seated and still for resting HR, and only for the brief effort step when you're cleared for light activity. Don't run checks while driving, operating machinery, or in any situation where looking at your phone or exerting yourself briefly would be unsafe.
Place your finger properly over the camera and flash as directed; poor contact causes failed or unreliable captures. Cardia is not a substitute for professional medical advice, treatment, or emergency response.
No warranty
Cardia is provided "as is." I do my best to ship something that works well, but I can't guarantee it's bug-free, fits every purpose, or will keep working forever. To the extent the law allows, I'm not promising anything about it beyond what's stated here.
Liability
To the fullest extent the law allows, I'm not liable for indirect, incidental, special, consequential, or punitive damages — lost profits, lost data, lost time, anything like that — that come from using or not being able to use Cardia. If I am liable for something, the total amount I owe you for everything combined is capped at the greater of (a) what you paid me through Apple in the last 12 months, or (b) CAD $10.
Some places don't allow these limits, in which case they apply only as far as the local law permits.
Apple's role
These terms are between you and me (Koirala Studio), not Apple. Apple has no responsibility for Cardia or its contents. If Cardia fails to live up to a warranty, you can let Apple know and they may refund you. Apple is allowed to enforce these terms against you as a third-party beneficiary.
If the app changes or stops
I might update or discontinue Cardia. If I do something that affects paying subscribers, I'll give reasonable notice through the App Store or inside the app.
If these terms change
I'll update the date at the top and surface a notice inside Cardia for material changes. Continuing to use the app after a change means you accept the updated terms.
Ending things
Delete the app whenever you want — that ends your use of it. If you break these terms badly, I may need to cut off your access. The liability and warranty sections survive even after the agreement ends.
Where this is governed
These terms are governed by the laws of Ontario, Canada. Any disputes go to the courts of Ontario. If you're a consumer, this doesn't strip you of mandatory protections under the laws of your own home jurisdiction.
Contact
Koirala Studio · Ontario, Canada
support@koirala.studio