privacy policy

1. What stays on your device, including face, depth and body-position data

Cornblock uses Apple’s Screen Time, Family Controls, Managed Settings, Device Activity, Safari extension, notification, and camera features to provide blocking, reset, and progress features. Your selected apps, websites, categories, custom website entries, blocking schedules, usage reports, streak, settings, and any optional relapse note are stored and used on your device and its app group.

The Family Activity Picker gives Cornblock privacy-preserving selection tokens rather than a server-side list of the apps or sites you selected. Cornblock does not send your selected apps, selected sites, browsing history, page content, usage reports, or relapse-note text to Cornblock’s servers.

Two optional features do send something off your device when you use them: photo quests, and the replies Cornelius writes to a pledge or urge note. Section 2 says exactly what leaves, where it goes, and what happens to it. Neither is needed to block sites, and you can skip both.

Cornblock has two optional camera exercises, push-ups and squats. You can do them as a reset or as a timed set from the Home screen. Both work entirely on your iPhone.

Both exercises use the front camera with the phone standing up in front of you: on the floor for push-ups, on a chair or stool for squats. While the exercise screen is open, the live picture from the camera is shown on your screen so you can see yourself. Apple’s Vision framework, running on your iPhone, marks the approximate position of your head, shoulders, elbows, wrists, hips, knees and ankles in that picture. Cornblock uses those positions to draw a guide over the picture, to check that you are in the starting position, and to count a repetition each time your shoulders go down and come back up. Neither exercise uses face tracking or depth data.

Versions of Cornblock before 1.3 counted push-ups differently, with the phone lying flat on the floor. On iPhone models with a TrueDepth camera, those versions use Apple’s ARKit face tracking to measure a single value: the distance between the front-facing camera and your face. That distance rising and falling is how the app recognises that a repetition was completed. Face tracking runs only while the push-up screen is open, and stops when you leave it. If you use one of those versions, everything in this section applies to that measurement too.

Cornblock does not collect, store, or transmit your face or your image. The camera picture is processed in memory on your iPhone one frame at a time and is never recorded or saved. The body positions read from it, the face distance, a flag indicating whether a face is in view, and timestamps are held in memory only while the exercise screen is open, and are discarded when it closes. The app never receives a face mesh, facial geometry, facial expressions, or any biometric template or identifier from the TrueDepth camera.

• Face, depth and body-position data is used solely to count push-up and squat repetitions, check your position and draw the on-screen guide during a camera exercise, and for no other purpose.
• Face, depth and body-position data is never used to identify or authenticate you, and never used to recognise or identify any anonymous individual.
• Face, depth and body-position data is never shared with, disclosed to, or sold to any third party, including advertising networks, analytics providers, and data brokers.
• Face, depth and body-position data is never used for advertising or marketing, and never used to build a profile of you.
• Face, depth and body-position data is never transmitted off your device. It is never sent to Cornblock’s servers and is never stored on any server.
• Face, depth and body-position data is never written to permanent storage on your device, and nothing derived from it is retained after the exercise closes.
• Camera exercises are optional. You can complete a reset using a different method, and you can decline or revoke camera access in iOS Settings at any time.

2. Information we receive or collect

We only collect information that is needed to run the Services, communicate with you, understand whether the product works, and meet legal obligations. That information can include the following.

• Subscription information: Apple processes App Store payments. RevenueCat helps us determine available products and whether your Cornblock Pro entitlement is active. We receive subscription, transaction, entitlement, and device-level identifiers needed for that purpose; we do not receive or store your full payment-card number.
• Product analytics: when enabled in the app, PostHog receives pseudonymous device and app-use information, such as app screens, interactions with identified controls, onboarding stage, feature events, subscription status, counts, and timing. We configure these events for product improvement and do not intentionally send browsing history, named selected apps or sites, or the text of your relapse note.
• Screen recording: when analytics is enabled, PostHog records the screens of the setup flow that follows a purchase, so that we can see where setup goes wrong. Recording starts when that flow begins and stops when you leave it. Nothing else in the app is recorded: not the block screen, the reset and intervention screens, your statistics, or anything you reach from Home. Text you type and images on screen are masked on your device before a recording is sent, so a recording shows the layout and where you tapped rather than what it said.
• Advertising measurement: Cornblock uses Meta’s SDK to understand whether an advertisement led to an app install or a subscription. Meta receives app events such as an install, an app launch, and a completed purchase, along with the device and app information needed to attribute them. The device advertising identifier is sent to Meta only if you allow tracking when iOS asks; if you decline, or are never asked, it is not collected. We do not send Meta your blocking selections, browsing history, selected apps or sites, or the text of your relapse note.
• Apple Ads measurement: Cornblock asks Apple’s AdServices framework for a token that says whether the app was installed from an Apple Ads campaign, and passes it to RevenueCat, which asks Apple for the campaign details. This lets us see which campaigns lead to subscriptions. It uses no advertising identifier and does not depend on tracking permission.
• App updates: each time Cornblock starts, it asks Expo’s update service whether a newer version of the app’s code is available, and downloads it if there is one. This is how we deliver fixes between App Store releases. The request carries the app version, which update the app is running and whether the last one failed to start, and a random identifier created when the app is installed, which Expo uses to count devices and to release an update to a share of them first. It carries nothing about you, your selected apps or sites, or what you browse.
• Photo quests: some daily quests ask for a photo as proof, for example of the sky or the outdoors. When you submit one, the photo is sent over an encrypted connection to Cornblock’s server, reduced in size, and passed to OpenAI’s model, which returns only whether the photo matches the quest. Cornblock’s server does not write the photo to storage, and we call OpenAI with storage turned off; OpenAI does not use API data to train its models. What we keep is a record of the check — which quest, whether it passed, how long it took, and an anonymous request identifier — never the picture. A copy of the photo can be saved in the app on your phone to show in your log, and that copy stays on your device.
• Cornelius replies: when you make a pledge or log an urge, you can write a short note about how you feel or what set the urge off, and Cornelius replies to it. To write that reply, your note and your answers on that screen — a mood or intensity setting and the reason you picked — are sent over an encrypted connection to Cornblock’s server and passed to OpenAI’s model, which returns the reply. Cornblock’s server does not store the note or the reply, and the request is made with OpenAI’s storage turned off. The note itself stays on your device with your pledge or urge log. We record that a reply was generated and how long it took, not what it said.
• Support and feedback: if you email us or use the in-app feedback form, we receive the message you write and, if you choose to add one, your email address so that we can reply. Feedback is stored in our database, hosted by Supabase, together with an anonymous per-install identifier that is used only to limit how many messages one install can send.
• Website analytics: the website uses Vercel Analytics and PostHog to understand aggregated visits, which link or channel a visitor arrived from, and page performance. PostHog stores an identifier in your browser so that repeat visits are not counted as separate people. We do not use advertising pixels or sell website visitor data for targeted advertising.
• Former launch waitlist records: if you joined Cornblock’s waitlist before the app launched, we may retain the email address and signup metadata you previously submitted until you unsubscribe or ask us to delete it. The website no longer accepts waitlist signups.

3. How we use information

We use the information above to provide and secure the Services; manage subscriptions and restore purchases; answer support requests; diagnose bugs; understand feature use; comply with law; and protect Cornblock, our users, and others from misuse.

We do not sell or rent personal information. We do not use your blocking selections, browsing history, or app-usage reports for advertising.

Advertising measurement tells us which advertisements bring people to Cornblock. We do not use it to build a profile of you, and we do not target advertising based on what you browse or block.

Quest photos and Cornelius notes are used for one thing each: to check the photo against the quest, and to write the reply you see. They are not used for advertising, analytics, or to train any model, ours or anyone else’s.

4. When information is shared

We share limited information with service providers that help us operate the Services: Apple for App Store purchases and iOS functionality; RevenueCat for subscription management and Apple Ads attribution; PostHog for app and website analytics; Meta for advertising measurement and attribution; OpenAI for checking quest photos and writing Cornelius’s replies; Supabase for feedback records and former launch-waitlist records; Expo for delivering app updates; Vercel for hosting Cornblock’s website and API, and for website analytics; and email providers when you contact us. These providers process information under their own terms and privacy policies and only as needed to provide their services.

We may also disclose information if required by law, to protect rights or safety, or as part of a corporate transaction such as a merger, financing, or acquisition. Aside from the advertising measurement described above, we do not share personal information for third-party advertising, and we never share your blocking selections, browsing history, selected apps or sites, or relapse notes with any advertising network.

5. Retention and your choices

Local Cornblock data remains on your device until you remove or reset it, or remove the app, subject to your device’s own storage behavior. You can change Screen Time, notification, and camera permissions in iOS settings. Removing a permission can limit or stop the related feature.

Quest photos and Cornelius notes are processed and discarded as described in section 2; we hold no copies to return or delete. We retain former launch-waitlist records until you unsubscribe or ask us to delete them. We retain support, feedback, analytics, and subscription records only for as long as reasonably necessary for the purposes described here, including support, security, fraud prevention, and legal obligations.

Depending on where you live, you may have rights to request access, correction, deletion, or other control of personal information we hold about you. Email hello@cornblock.app to make a request. Because your core blocking and usage data stays on your device, we cannot retrieve it for you from our servers.

6. Security, international processing, and children

We use reasonable safeguards designed to protect information, but no service can guarantee absolute security. Our service providers may process information in countries other than yours; where required, we use appropriate safeguards for those transfers.

Cornblock is not directed to children under 13, and we do not knowingly collect personal information from them. If you believe a child has provided personal information to us, contact hello@cornblock.app so we can address it.

7. Changes and contact

We may update this Privacy Policy as Cornblock changes. If we make a material change, we will update the date above and provide additional notice when appropriate. For privacy questions, requests, or concerns, contact hello@cornblock.app.