Terms of Service.

RhythmBio charts four biorhythm cycles computed from your date of birth and turns them into daily scores, forecasts, briefings, journaling, and family tracking. By creating an account you agree to these terms. RhythmBio is operated by Darryll Stephen, trading as RhythmBio, a sole trader based at 4th Floor, Silverstream House, 45 Fitzroy Street, Fitzrovia, London, W1T 6EB, United Kingdom — that's who you're contracting with.

RhythmBio is a self-reflection tool, not a medical device or a source of medical, psychological, or professional advice. Biorhythm theory is a contested framework: the fixed cycle periods have not been validated in controlled scientific studies. Never use the app to make decisions about your health, medication, treatment, or safety, and never delay seeking professional advice because of something the app told you. If a briefing and your doctor disagree, listen to your doctor.

You must be 16 or older. Keep your credentials to yourself and give us accurate information. The app literally runs on your date of birth. You're responsible for activity on your account. If you add family members, make sure you're entitled to share their details with us.

The free tier is free forever for individual use. New accounts also get a 7-day trial of Pro at no cost. Pro is a paid subscription billed in GBP through Stripe, renewing automatically each month or year until cancelled. You can cancel any time from Settings; cancelling stops future renewals, and access continues until the end of the period you've already paid for. Prices may change with notice before your next renewal.

Payments are non-refundable, including for partial billing periods and past renewals, except where required by law. If you're a consumer in the UK or EU, you have a statutory right to cancel within 14 days of first subscribing and receive a full refund; by using Pro during that window you agree that you're requesting the service to start straight away, and that this cancellation right ends once you've made active use of it. Nothing in this section affects your other statutory consumer rights.

Don't abuse the service: no attempting to break, probe, or overload it, no scraping other people's data, no reselling access, and no using the AI briefings to generate content that's unlawful or harmful. We can suspend accounts that do.

Your journal entries and data remain yours; you give us the licence needed to store and process them to run the service. The RhythmBio name, design, and software remain ours. We work hard to keep the service up, but it's provided “as is”. To the maximum extent the law allows, we're not liable for indirect losses, and our total liability is capped at the amount you paid us in the twelve months before a claim.

You can delete your account from Settings whenever you like. It takes your data with it. We may terminate accounts that breach these terms, and we'll refund any unused subscription period if the termination wasn't your fault.

If we change these terms materially we'll update the date above and notify subscribers by email before the change takes effect. Questions: hi@rhythmbio.app.