Version v2 — Effective date: April 28, 2026
By downloading, installing, or using Zeus Focus Stacking (the "App") or by visiting zeusfocusstacking.com (the "Website"), you agree to be bound by these Terms of Service ("Terms"). If you do not agree, do not use the App or the Website.
The App and the Website are operated by Zeus Focus Stacking, an independent app project based in Switzerland ("we", "us", "our"). These Terms form a binding agreement between you and us.
Zeus Focus Stacking is a GPU-accelerated focus stacking application for iPhone and iPad. Core functionality includes image capture, image alignment, focus stacking, and gallery management. A companion Website hosts the Picture of the Week showcase described below.
Subject to these Terms, we grant you a limited, non-exclusive, non-transferable, revocable license to use the App on any Apple device that you own or control, as permitted by the Apple App Store Terms of Service.
The App is available in two tiers:
Zeus Focus Stacking Pro is offered as an auto-renewable subscription with the following plans:
Prices are shown at point of purchase and may vary by region. Apple may convert CHF to your local currency.
Subscriptions are charged to your Apple ID at confirmation of purchase. Subscriptions automatically renew at the end of each billing period (one month or one year, as applicable) unless auto-renew is turned off at least 24 hours before the end of the current period. Your Apple ID will be charged for renewal within 24 hours prior to the end of the current period.
If you are eligible for the 7-day free trial on the yearly plan, you will not be charged during the trial period. If you do not cancel at least 24 hours before the trial ends, your subscription will automatically convert to a paid yearly subscription and your Apple ID will be charged at the then-current yearly price. Only one free trial per Apple ID is available.
You can manage your subscription and turn off auto-renewal at any time in your Apple ID account settings: Settings → [your name] → Subscriptions. Cancellation takes effect at the end of the current billing period; you will retain Pro access until that date. No partial refunds are issued for unused periods.
All subscription purchases are processed by Apple and are subject to Apple's refund policies. We do not process, store, or have access to payment information. Refund requests must be submitted directly to Apple via reportaproblem.apple.com.
Users who purchased the legacy one-time Pro upgrade prior to the introduction of the subscription model retain permanent Pro access tied to their Apple ID at no additional cost.
The following features require an active Pro subscription (or a legacy one-time purchase):
Participation in Picture of the Week is entirely free and does not require a subscription. See Section 5.
Picture of the Week is a curated photographic showcase. Participation is completely free of charge. No purchase, subscription, payment, or other consideration of any kind is required to submit an image or to be selected.
All submissions are rendered and transmitted to our servers at identical full quality, regardless of whether the submitter has a Pro subscription, a legacy purchase, or no purchase at all. The technical quality of a submission is therefore independent of any payment made to us.
Submissions are reviewed by a private jury designated by Zeus Focus Stacking. The jury may consist of one or more persons invited privately by us. The jury reviews submissions internally using its own operational tools. No public voting, ranking, rating, score, or metric is exposed to users or submitters at any time.
The jury evaluates submissions based on subjective artistic and aesthetic taste. Final selection authority rests exclusively with Zeus Focus Stacking, whose decision is subjective, final, non-appealable, and binding in case of any ambiguity, tie, or disagreement within the jury.
Picture of the Week is not a lottery, sweepstake, competition, contest of chance, or prize contest within the meaning of the Swiss Federal Act on Money Gaming (LGD / SR 935.51) or comparable legislation in other jurisdictions. It is a curated editorial showcase where selection is entirely at the curator's discretion and is not based on chance, objective merit, or any public voting mechanism. No entry fee, purchase, or consideration is required for participation or selection.
Picture of the Week awards no monetary or material prize, gift, voucher, or other reward of any kind. The only outcome of being selected is public recognition: the winning image and the author name provided by the submitter are displayed on the Website. There is no entry fee, no payment to participate, and no payment, gift, or consideration of any kind issued to the selected submitter. No submitter has any legal claim to any form of compensation arising from selection.
Submitted images are uploaded at full ("master") resolution and are not displayed publicly during the jury review. Only the image selected as the Picture of the Week becomes publicly visible, and only on the Picture of the Week page of the Website. Non-selected submissions are not surfaced on the Website and are deleted in accordance with Section 5.9.
To submit to Picture of the Week you must:
The submission interface in the App requires explicit confirmation of the above before a submission is accepted.
By submitting, and only if your image is selected as the Picture of the Week or progresses through the jury review stages in a way that warrants public display, you grant Zeus Focus Stacking a non-exclusive, royalty-free, perpetual, worldwide license to display the submitted image together with your provided author name on the Website and in reasonable promotional material connected to Picture of the Week. You retain all other rights in your image. This license is revocable upon written request (see Contact); we will remove the image from the Website within a reasonable period after receiving a valid revocation request.
See our Privacy Policy for details. In summary: we collect the image, the author name you provide, an optional title/caption, consent confirmations, the pseudonymous Contribution ID generated on your device, and limited technical metadata, strictly for the purposes of jury review, internal status tracking, and publication on the Website in the event of selection. We do not ask for, collect, or use email addresses for Picture of the Week submissions.
Submissions that are not selected as the Picture of the Week are automatically deleted from our servers within 90 days of submission. Selected winning submissions may be retained indefinitely for the purpose of maintaining the Picture of the Week archive on the Website.
You may request the removal of your submission or your already-published winning image at any time by contacting us at the address in Contact. We will honor valid removal requests within a reasonable period.
The composition of the jury (whether a single curator or a multi-person panel, and its members' identities) is private and not disclosed. This preserves the editorial independence of the selection process.
We may modify, suspend, or discontinue Picture of the Week at any time, for any reason, without notice. No pending submission creates a legal expectation of review, selection, or publication.
Zeus Focus Stacking offers a feature called "Contribute to Engine Improvement", available from the actions of any saved project. The Program lets you donate a complete capture (all original bracket frames plus the resulting stacked image) so we can use it as a research input to test and improve the alignment and stacking algorithms. Participation is entirely voluntary, free, and has no impact on App functionality, Pro entitlement, or anything else.
Nothing is uploaded until you tap the button, optionally enter a comment, tick the consent checkbox in the submission sheet, and confirm. The consent flag is recorded locally so you are not asked again on subsequent contributions; you can revoke consent at any time by contacting us at privacy@zeusfocusstacking.com.
Contributed projects are used strictly as test inputs against new algorithm builds and tuning experiments. We do not publish, display publicly, share with any third party (other than Google LLC as Firebase processor), use in marketing material, train any commercial machine-learning model with intent to redistribute, or otherwise use contributed images or frames for any purpose other than internal engine engineering.
By contributing, you grant Zeus Focus Stacking a non-exclusive, royalty-free, worldwide license to store, process, and run software analyses on your contributed image data for the sole purpose described in section 6.3. You retain all other rights in your image. This license is revocable at any time as described in section 6.2; upon a valid revocation we will delete your contribution within a reasonable period.
See the Privacy Policy — Engine Improvement Program for the precise list of fields transmitted. In summary: the original bracket frames, the stacked result, an optional comment, a small set of technical metadata (frame count, image dimensions, device model, iOS version, App version, engine version), and an anonymous Firebase identifier scoped to your device.
The Engine Improvement Program is intended for adult photographers. By contributing you confirm that you are the sole author of the submitted material and that you have all necessary rights to share it.
You may not:
Your content: You retain all rights to the photos and images you create using Zeus Focus Stacking. The App does not claim any ownership or license over your content, except as expressly granted in Section 5.7 in the specific case of a selected Picture of the Week submission.
Our content: The App, the Website, including their code, Metal shaders, algorithms, design, graphics, and documentation, are protected by copyright and other intellectual property laws. All rights not expressly granted in these Terms are reserved.
The App and the Website are provided "as is" and "as available" without warranties of any kind, either express or implied, including but not limited to:
Image processing results depend on many factors including source image quality, camera movement, and subject characteristics. We do not guarantee specific output quality. Picture of the Week selection is a subjective editorial process and we make no warranty that any submission will be reviewed, selected, or acknowledged.
To the maximum extent permitted by applicable Swiss law, in no event shall Zeus Focus Stacking be liable for any indirect, incidental, special, consequential, or punitive damages, including but not limited to loss of data, loss of photos, or loss of profits, arising from your use of the App or the Website.
Our total liability for any claims related to the App or the Website shall not exceed the amount you paid to us, via Apple, in the twelve (12) months preceding the claim.
Zeus Focus Stacking requires iOS 17.0 or later and a compatible iPhone or iPad. Performance and available features may vary by device. The App uses the device GPU extensively; results and processing speed depend on your device's hardware capabilities.
We may release updates to the App from time to time. Updates may modify or remove features. Your continued use of the App after an update constitutes acceptance of any changes.
These Terms are effective until terminated. Your rights under these Terms will terminate automatically if you fail to comply with any of them. We may also terminate or suspend your access to Picture of the Week or the Engine Improvement Program at any time, for any reason, at our sole discretion. Upon termination, you must cease all use of the App and delete all copies from your devices. Sections 8, 9, 10, 14 survive termination.
These Terms shall be governed by and construed in accordance with the substantive laws of Switzerland, excluding its conflict-of-laws rules and excluding the United Nations Convention on Contracts for the International Sale of Goods.
Any disputes arising out of or in connection with these Terms shall be subject to the exclusive jurisdiction of the ordinary courts of the Canton of Zürich, Switzerland, subject to any mandatory consumer protection provisions granting a consumer the right to bring proceedings in their country of residence.
These Terms are between you and us, not Apple. Apple has no obligation to furnish maintenance or support services for the App. Apple is not responsible for any claims related to the App, including product liability, consumer protection, and intellectual property claims. In the event of a third-party intellectual property claim, we (not Apple) are responsible for investigation and defense. Apple and its subsidiaries are third-party beneficiaries of these Terms and, upon your acceptance, will have the right to enforce these Terms against you as a third-party beneficiary.
We reserve the right to modify these Terms at any time. Material changes will be notified at least 30 days in advance through an in-App notice or the Website. Updated Terms will be posted on this page with a revised effective date and version number. Continued use of the App after the effective date constitutes acceptance of the updated Terms.
For questions about these Terms, subscription billing, Picture of the Week, or to exercise any right mentioned in these Terms, contact us at:
Zeus Focus Stacking
Independent app project based in Switzerland
Email: legal@zeusfocusstacking.com