Privacy

Last updated: 7 August 2026

This Privacy Policy explains how Day 100 (“Day 100”, “we”, “us”) collects, uses, and protects your information when you use the Day 100 mobile app and related websites at day100.co and day1.at (together, the “Service”). Day 100 is operated by Little Polar Apps Ltd, a company registered in England & Wales, based in Ipswich, United Kingdom. For the purposes of UK data protection law, Little Polar Apps Ltd is the data controller.

Information we collect

  • Account information. When you create an account we collect your email address and a password. If you sign in with Apple or Google, we receive your name and email address from that provider.
  • Profile information. Your display name, optional username and avatar, and the preferences you set during onboarding: fitness level, goals, and preferred time of day.
  • Activity data. The challenges you create and your daily check-ins — including targets, what you logged, streaks, grace days, and completion dates. This is the core data that powers your 100-day grid.
  • Subscription information. If you purchase Day 100 Pro, we and our subscription provider receive your purchase and entitlement status and a subscription identifier. Your payment is processed by Apple or Google; we never receive your full card details.
  • Support communications. Any information you choose to send us when you contact us for support.
  • Technical information. Basic device and app information needed to operate and secure the Service. We do not use third-party advertising or cross-app tracking, and we do not sell your personal data.

How we use your information

  • To provide the Service — create your account, track your challenges and check-ins, calculate streaks, and render your grid.
  • To send you the daily reminders you enable. Reminders are scheduled locally on your device; you can turn them off at any time in Settings.
  • To manage your subscription and unlock Pro features.
  • To generate AI training plans, where available. When you request a plan, your profile details (such as fitness level, goals, and schedule) are sent to our backend, which uses a third-party AI service to produce the plan. We do not send your plan requests to advertisers.
  • To enable sharing. When you share a challenge, we generate a short link (via day1.at) to a public preview page showing your challenge and progress. Anyone with the link can view that page, so only share it with people you choose.
  • To respond to your requests, keep the Service secure, prevent abuse, and meet our legal obligations.

Legal bases (UK/EU users)

We process your information to perform our contract with you (providing the Service), on the basis of your consent (for example, notifications), for our legitimate interests (keeping the Service secure and improving it), and to comply with our legal obligations.

Service providers

We share information with trusted providers who process it on our behalf, only as needed to run the Service:

  • Supabase — hosts our database, authentication, and file storage. Your account and activity data are stored here, in a data centre in the United Kingdom / European Union.
  • RevenueCat — manages subscription status and entitlements.
  • Apple and Google — provide sign-in and process subscription payments through the App Store and Google Play.
  • Stripe — processes payments for trainer plan purchases, where that feature is available.
  • Cloudflare — delivers and secures our websites and the day1.at short links.
  • Our backend (Expanse) at day100.co / api.day100.co, and the third-party AI service it uses to generate training plans.

International transfers

Some of our providers are based outside the United Kingdom, including in the United States. Where personal data is transferred internationally, we rely on appropriate safeguards such as the UK International Data Transfer Agreement or Standard Contractual Clauses.

Data retention

We keep your information for as long as your account is active. If you delete your account, we delete or anonymise your personal data, except where we must retain certain records (such as transaction records) to meet legal or accounting obligations.

Your rights

Depending on where you live, you may have the right to access, correct, delete, restrict, or object to our processing of your personal data, to data portability, and to withdraw consent. To exercise any of these rights, or to request deletion of your account and data, email us at [email protected]. You also have the right to complain to the UK Information Commissioner’s Office (ICO) at ico.org.uk.

Children

Day 100 is not directed to children under 13, and we do not knowingly collect personal data from children under 13. If you believe a child has provided us with personal data, please contact us and we will delete it.

Security

We protect your information using encryption in transit, access controls, and reputable infrastructure providers. No method of transmission or storage is completely secure, but we work to protect your data and to respond promptly to any issues.

Changes to this policy

We may update this Privacy Policy from time to time. When we do, we will revise the “Last updated” date above and, where appropriate, notify you in the app.

Contact us

Questions about this policy or your data? Email [email protected].
Little Polar Apps Ltd, Ipswich, United Kingdom.