Terms of Use — AvGrav

Last updated: August 24, 2026

These Terms of Use ("Terms") are a legal agreement between you and AvGrav ("we," "us," "our") governing your use of the AvGrav app, including its Home Screen widgets and Apple Watch app (together, the "App"). By using the App, you agree to these Terms. If you do not agree, do not use the App.

1. Eligibility

You must be at least 13 (or the minimum age of digital consent in your country). If you are under 18, you may use the App only with the consent and supervision of a parent or legal guardian.

2. Reference tool only — not a certified measurement instrument

AvGrav is a general-purpose reference and convenience tool for petroleum API gravity temperature correction. It is NOT a certified, calibrated, or approved measurement instrument, and it is NOT a substitute for a physical calibrated hydrometer, thermometer, correction table, or your organization's official fuel-quality, fuel-acceptance, or fuel-rejection procedures. The App performs the published API MPMS Chapter 11.1 correction calculation based entirely on the values you type in; it has no way to verify that those values are accurate, that your equipment is calibrated, or that the reading reflects the actual condition of any fuel. Any error in what you enter, any equipment miscalibration, and any rounding or numerical difference versus a physical reference tool will carry through to the App's result without warning.

You are solely responsible for every decision made about fuel quality, fuel acceptance, or fuel rejection. Do not use the App as your sole basis for accepting or rejecting a fuel load, releasing fuel for use, or making any decision where contaminated, off-specification, or otherwise unsafe fuel could cause injury, death, property damage, or damage to an aircraft, vehicle, vessel, or other equipment. Always confirm results against your organization's official written procedures, a properly calibrated physical reference tool, and, where required, a qualified fuel-quality-control professional, before acting on them.

3. Not affiliated with any standards body or equipment manufacturer

The App implements the publicly published API MPMS Chapter 11.1 correction formula, which is a public reference standard, not proprietary software. AvGrav is an independent product, written from scratch, and is not affiliated with, endorsed by, or sponsored by the American Petroleum Institute, ASTM International, Gammon Technical Products, or any other standards body or equipment manufacturer. Any resemblance to another company's product name, branding, or user interface is unintentional.

4. Accuracy and "as is"

THE APP IS PROVIDED "AS IS" AND "AS AVAILABLE," WITHOUT WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, ACCURACY, TITLE, AND NON-INFRINGEMENT. We do not warrant that the App's calculations are error-free, that the App will be uninterrupted or bug-free, or that results will match any specific physical reference tool, official table, or another calculator.

5. License and acceptable use

We grant you a limited, personal, non-exclusive, non-transferable, revocable license to use the App for your own purposes. You agree not to copy, modify, distribute, sell, or sublicense the App; reverse engineer it except as permitted by law; circumvent security or licensing; or use it unlawfully.

6. Purchases and payments

The App is a one-time paid download. This is a one-time purchase, not a subscription: there are no recurring charges. Purchases are processed by Apple and subject to Apple's terms; refunds and billing are handled solely by Apple.

7. Limitation of liability

TO THE MAXIMUM EXTENT PERMITTED BY LAW, IN NO EVENT WILL WE BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, EXEMPLARY, OR PUNITIVE DAMAGES, OR FOR ANY LOSS OF PROFITS OR REVENUE, DATA, OR GOODWILL, ANY FINANCIAL, BUSINESS, OR ECONOMIC LOSS, ANY COST OF SUBSTITUTE FUEL, EQUIPMENT, OR SERVICES, ANY LOSS OR DAMAGE ARISING FROM CONTAMINATED, OFF-SPECIFICATION, MISFUELED, OR OTHERWISE UNSAFE FUEL, ANY LOSS ARISING FROM DECISIONS MADE OR ACTIONS TAKEN (OR NOT TAKEN) IN RELIANCE ON THE APP OR ITS CALCULATIONS, OR FOR PERSONAL INJURY, DEATH, OR PROPERTY DAMAGE (INCLUDING TO ANY AIRCRAFT, VEHICLE, VESSEL, OR EQUIPMENT), ARISING OUT OF OR RELATING TO YOUR USE OF (OR INABILITY TO USE) THE APP, UNDER ANY LEGAL THEORY, EVEN IF ADVISED OF THE POSSIBILITY. YOU AGREE THAT YOU USE THE APP ENTIRELY AT YOUR OWN RISK, THAT THE APP IS ONE INPUT AMONG MANY YOU MUST INDEPENDENTLY VERIFY, AND THAT WE ARE NOT FINANCIALLY RESPONSIBLE FOR ANY LOSS YOU OR ANY THIRD PARTY MAY INCUR, INCLUDING ANYONE INVOLVED IN FUELING OPERATIONS YOU SUPERVISE, DIRECT, OR PARTICIPATE IN. OUR TOTAL AGGREGATE LIABILITY WILL NOT EXCEED THE GREATER OF (A) THE AMOUNT YOU PAID US IN THE 12 MONTHS BEFORE THE CLAIM, OR (B) US $50. Nothing in this Section limits any liability that cannot be excluded or limited under applicable law.

8. Assumption of risk and indemnification

You knowingly assume all risk arising from your use of the App, including risk to yourself and to any third party present during or affected by a fueling operation informed by the App. You agree to indemnify, defend, and hold harmless AvGrav from any claims, losses, liabilities, damages, and expenses (including reasonable attorneys' fees) arising out of your use or misuse of the App, your violation of these Terms, or your violation of any law, safety regulation, or third-party right.

9. International use and export compliance

The App is operated from the United States. If you use it elsewhere, you are responsible for compliance with applicable local laws, including fuel-handling and safety regulations. You agree to comply with all applicable export-control and economic-sanctions laws, including the U.S. Export Administration Regulations (EAR) and regulations administered by the U.S. Department of the Treasury's Office of Foreign Assets Control (OFAC). You represent that you are not located in, and will not use, download, or export the App in or to, any U.S.-embargoed country or region, and that you are not on, and will not use the App on behalf of, the U.S. Treasury's Specially Designated Nationals list or any other U.S. government restricted- or denied-party list.

10. Intellectual property

The App, including its name, code, and original written content, is owned by AvGrav and protected by intellectual-property laws to the extent such protection is available. The underlying API MPMS Chapter 11.1 correction formula is a publicly published reference standard and is not our intellectual property. Some visual assets (such as app icons and imagery) were created with the assistance of generative-AI tools; the copyright status of AI-assisted works varies under current U.S. Copyright Office guidance and depends on the degree of human creative authorship involved, and we make no representation about the scope of any copyright protection in those specific assets. We do not claim ownership of, and do not intend to infringe, any third party's trademarks, copyrights, or other rights, and any resemblance is unintentional.

If you believe content in the App infringes your rights, email avclock@protonmail.com identifying the content, your right and proof of it, your contact information, and a good-faith statement, and we will review properly documented requests and, where appropriate, promptly remove or replace the material.

11. Privacy

Your use is also governed by our Privacy Policy. AvGrav makes no network requests at all and has no analytics or crash-reporting of its own, so it does not collect or transmit personal data. Apple separately and independently handles your purchase receipt and, if you have opted in at the iOS level, anonymous device diagnostics: that processing is governed by Apple's own privacy policy, not this one.

12. Termination

These Terms apply until terminated. We may suspend or terminate your license if you breach them. Sections that by their nature should survive (disclaimers, limitation of liability, indemnification, governing law) will survive.

13. Changes

We may update these Terms and the Privacy Policy from time to time. For changes we consider material — including anything affecting the safety disclaimers, liability, or dispute-resolution provisions — the App will require you to review and affirmatively re-accept the updated documents the next time you open it before you can continue using it. For non-material changes (such as clarifications, corrections, or formatting), the updated "Last updated" date reflects the change, and your continued use of the App after that date constitutes acceptance of the revised Terms.

14. Governing law and dispute resolution

These Terms are governed by the laws of the State of Florida, USA, without regard to conflict-of-laws rules.

Informal resolution first. Before bringing any claim, you agree to email avclock@protonmail.com and try to resolve the dispute informally for at least 30 days.

Binding individual arbitration. Except as stated below, any dispute arising out of or relating to these Terms or the App that is not resolved informally will be settled by final and binding arbitration on an individual basis, administered under the rules of a recognized arbitration body, rather than in court, and conducted in or under the laws of Florida.

Class-action waiver. You and we agree that each may bring claims only in an individual capacity, and not as a plaintiff or class member in any class, collective, consolidated, or representative proceeding. The arbitrator may not combine more than one person's claims.

Exceptions. Either party may (a) bring an individual claim in small-claims court, and (b) seek injunctive or equitable relief in the state or federal courts located in Florida to protect intellectual-property or proprietary rights.

Opt-out. You may opt out of this arbitration agreement within 30 days of first accepting these Terms by emailing avclock@protonmail.com; if you opt out, disputes will be resolved in the state or federal courts located in Florida.

Nothing in this section limits rights that cannot be waived under the mandatory consumer-protection laws of your country of residence.

15. Severability; entire agreement; no waiver

If any provision is unenforceable, the rest remain in force. These Terms (with the Privacy Policy and Apple's applicable terms) are the entire agreement regarding the App. Our failure to enforce any provision is not a waiver.

16. Apple-required acknowledgments

These Terms are between you and AvGrav only, not Apple; we are solely responsible for the App. Apple has no obligation to provide maintenance or support. If the App fails to conform to any applicable warranty, you may notify Apple and Apple will refund the purchase price (to the extent applicable); Apple has no other warranty obligation. Apple is not responsible for claims relating to the App. Apple and its subsidiaries are third-party beneficiaries of these Terms and may enforce them.

17. Contact

Questions? Contact avclock@protonmail.com