Last updated: March 25, 2026
By downloading, installing, accessing, or using Defog ("the app," "the service"), you acknowledge that you have read, understood, and agree to be bound by these Terms & Conditions ("Terms"). If you do not agree, do not use the app. These Terms constitute a legally binding agreement between you ("user," "you") and M.J. Nauta ("we," "us," "our"), the operator of Defog.
Defog is a wellness and self-tracking application designed to help users log lifestyle and health-related data, identify potential patterns related to brain fog, and receive generated insights, recommendations, and self-experiments.
3.1 Defog is a wellness and self-tracking tool only. Defog is not a medical device, medical application, diagnostic tool, or healthcare provider. Defog has not been evaluated, approved, or cleared by the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), or any other regulatory body.
3.2 All content provided through Defog — including but not limited to insights, pattern analyses, recommendations, experiments, coaching suggestions, AI-generated content, educational materials, and any other information — is for general informational and educational purposes only. Nothing in Defog constitutes, is intended to constitute, or should be interpreted as:
3.3 Brain fog can be a symptom of numerous underlying medical conditions, some of which may be serious. You should always seek the advice of a qualified healthcare professional with any questions regarding a medical condition, symptoms, medications, supplements, or any health-related matter. Never disregard professional medical advice or delay seeking it because of information provided by Defog.
3.4 If you are experiencing a medical emergency, call your local emergency services immediately. Defog is not equipped to handle medical emergencies.
3.5 Defog's insights and recommendations are generated based on your self-reported data and general wellness information. They are inherently limited by the accuracy, completeness, and consistency of the data you provide. Defog does not have access to your medical history, lab results, genetic information, or clinical assessments unless you manually enter such information.
3.6 AI-powered features within Defog use artificial intelligence to analyze self-reported data. AI systems can produce inaccurate, incomplete, or misleading outputs. You acknowledge that AI-generated recommendations are automated suggestions, not professional advice, and should be independently verified before acting upon them.
3.7 You acknowledge and agree that any actions you take based on information provided by Defog are taken entirely at your own risk. We strongly recommend discussing any changes to your health routine with a qualified healthcare professional before implementation.
4.1 By using Defog, you expressly acknowledge and assume all risks associated with:
4.2 You understand that individual responses to lifestyle changes, supplements, dietary modifications, and other interventions vary significantly. What works for one person may not work for — or may be harmful to — another. Defog cannot predict your individual response to any recommendation or experiment.
4.3 You agree that you are solely responsible for your own health decisions and that Defog serves only as a tracking and informational tool to support — not replace — your own judgment and the guidance of qualified healthcare professionals.
To use Defog, you must create an account. You agree to:
You are responsible for all activity under your account.
Defog offers a free tier with core tracking features and a Premium subscription with advanced insights, recommendations, experiments, and additional features.
If you do not cancel before the trial period ends, your subscription will automatically convert to a paid subscription at the price displayed at the time of enrollment. You can cancel at any time during the trial through your Apple ID subscription settings.
All payments are processed exclusively through the Apple App Store. Subscription fees are charged in advance on a recurring basis (monthly or annually) through your Apple ID.
You can cancel your subscription at any time through your Apple ID settings (Settings → Apple ID → Subscriptions). Cancellation takes effect at the end of your current billing period. You retain Premium access until then.
All refund requests must be directed to Apple in accordance with Apple's refund policy. We do not process refunds directly.
We reserve the right to change subscription prices. You will be notified in advance. Changes take effect at the start of your next billing cycle.
7.1 You retain ownership of all data you enter into Defog. By using the app, you grant us a limited, non-exclusive, worldwide license to process, store, and analyze this data solely to provide the service.
7.2 You are responsible for the accuracy of data you provide. Defog's insights are only as reliable as the data you enter.
7.3 Your data is handled in accordance with our Privacy Policy.
You agree not to:
All content, design, graphics, code, algorithms, branding, and trademarks in Defog (excluding your personal data) are owned by or licensed to M.J. Nauta. You may not copy, modify, distribute, sell, or create derivative works without prior written permission.
TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, DEFOG IS PROVIDED ON AN "AS IS" AND "AS AVAILABLE" BASIS WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE.
We expressly disclaim all warranties, including but not limited to:
11.1 TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, IN NO EVENT SHALL MIRO NAUTA, OR ANY OF HIS AFFILIATES, AGENTS, CONTRACTORS, OR SERVICE PROVIDERS, BE LIABLE FOR:
11.2 IN ANY EVENT, OUR TOTAL CUMULATIVE LIABILITY SHALL NOT EXCEED THE GREATER OF (A) THE AMOUNT YOU PAID FOR DEFOG IN THE 12 MONTHS PRECEDING THE CLAIM, OR (B) FIFTY U.S. DOLLARS (USD $50.00).
11.3 THESE LIMITATIONS APPLY REGARDLESS OF THE THEORY OF LIABILITY AND EVEN IF WE HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
11.4 Some jurisdictions do not allow the exclusion or limitation of certain damages. In such jurisdictions, our liability shall be limited to the greatest extent permitted by applicable law.
You agree to indemnify, defend, and hold harmless M.J. Nauta from and against any claims, demands, damages, losses, liabilities, costs, and expenses (including reasonable attorneys' fees) arising from:
These Terms are governed by the laws of the Netherlands, without regard to conflict of law provisions.
Before filing any formal proceeding, you agree to attempt informal resolution by contacting support@defogapp.com. We will attempt to resolve the dispute within 30 days.
If informal resolution fails, legal proceedings shall be brought exclusively in the competent courts of the Netherlands.
To the maximum extent permitted by law, dispute resolution will be conducted only on an individual basis and not in a class, consolidated, or representative action.
14.1 By You: You may stop using Defog and delete your account at any time.
14.2 By Us: We may suspend or terminate your account at any time for violation of these Terms, abusive behavior, or fraudulent activity.
14.3 Survival: Sections 3 (Not Medical Advice), 4 (Assumption of Risk), 10 (Disclaimer of Warranties), 11 (Limitation of Liability), 12 (Indemnification), and 13 (Dispute Resolution) survive termination.
We may modify these Terms at any time. Continued use after changes constitutes acceptance. We will notify you of material changes through the app or by email.
If any provision is found invalid or unenforceable, the remaining provisions remain in full force.
These Terms, together with our Privacy Policy, constitute the entire agreement between you and M.J. Nauta regarding Defog.
Email: support@defogapp.com
Website: defogapp.com