Privacy policy

Last updated: 18 October 2026 · Version 1

This is a translation. If the two versions differ, the Spanish version prevails.

1. Who is responsible

The data controller for the processing described here is:

• Owner: Carlos Macías Martín, an individual based in Spain.
• Privacy contact email: support.stepin@gmail.com

Step In is a project by an independent developer and has no data protection officer (one is not required in this case). For any privacy question, write to the email above.

2. Your photos

Step In needs the camera to take two photos: the group photo (photo A) and the photo of the person who was missing (photo B). From them it creates a third one, the final photo, with everyone in it.

• Everything is processed on the phone. Separating people from the background, aligning the two photos and merging them all happen on your device. Neither we nor any server of ours receives the photos: we have no servers for that.
• It doesn't identify anyone. The app detects where people are in the image to cut them out, but it doesn't recognise faces, doesn't compare one person with another and doesn't know who is in the photo.
• Photos A and B. They are stored temporarily in the app's private storage, which other apps can't access, while the merge is done. Android may delete them to free up space, and they are removed when you uninstall the app or clear its data in Android settings.
• Final photo. When you tap Save, it is saved to your phone's gallery, in the Pictures/StepIn folder. From then on it's yours: you manage it with your gallery and delete it whenever you like. If you use a cloud photo backup (for example, Google Photos), that app may upload it according to its own settings, like any other photo.
• Sharing. If you tap Share, Android opens its share menu so you can choose which app to send it to. What happens next depends on that app.

The people in your photos also have rights over their image. Before posting or sharing a photo, make sure they are happy with it (see the terms of use).

3. Technical metadata in the photos

So that the second photo can be guided and the merge works well, the app adds technical data inside the photos themselves, in the UserComment field of their EXIF metadata:

• In photos A and B: the position and orientation of the phone when the photo was taken, measured in centimetres and degrees relative to where it was at the start (this is not a geographic location and contains no GPS coordinates); the camera calibration (focal length, sensor size, lens distortion) and exposure data (exposure time, ISO, white balance, focus); and the sensor's internal capture time.
• In the final photo: a technical report of the merge (image size, processing times and measurements of how well the two photos lined up).

This data doesn't identify anyone, doesn't include your location and isn't sent anywhere: it stays inside the files, on your phone. Note that if you share the final photo as a file, the technical report travels inside it, like any other photo metadata.

4. Google services used by the app

Step In doesn't send data to servers of its own. It uses two Google components that are installed and updated through Google Play:

Google Play Services for AR (ARCore)

This application runs on Google Play Services for AR (ARCore), which is provided by Google and governed by the Google Privacy Policy.

ARCore uses the phone's camera and motion sensors to work out how the phone moves between photo A and photo B. Step In only uses on-device motion tracking: it doesn't use ARCore's Cloud Anchors or Geospatial API, which are the features that send camera or location data to Google. If ARCore is not installed, the app asks you to install it from Google Play.

ML Kit (people segmentation)

To separate people from the background, Step In uses Google's ML Kit. The model is downloaded and updated on your device by Google Play services, and the images are analysed on the phone: the photos are not sent to Google.

According to the information published by Google, ML Kit sends Google some technical data for diagnostics and API usage statistics: device information (manufacturer, model, OS version, available accelerators), app information (package name and version), device or installation identifiers, performance metrics, API configuration, input and output sizes, event types and error codes. Google states that this data is encrypted in transit (HTTPS) and not transferred to third parties. Google handles it under its own privacy policy; we don't receive it.

5. App permissions

• Camera: to take photos A and B and for the augmented reality guide. It is requested the first time you take a photo. The app can't work without it.
• Storage (Android 7, 8 and 9 only): on those versions Android requires permission to save the final photo to the gallery. It's not needed on Android 10 and later.
• The app does not ask for access to your microphone, location, contacts or the photos already in your gallery.

6. Crash reports and usage statistics

Crash reports (Firebase Crashlytics)

Firebase Crashlytics is a Google service that helps us find and fix the app's bugs. It sends nothing on its own. If the app closes because of an error, Crashlytics stores a technical report on your phone without sending it. The next time you open the app it asks "Can you send us a technical report so we can fix it?" and the report only leaves the phone if you tap Send. If you tap Don't send or tap outside the prompt, the report is deleted from the phone without being sent. In the prompt you can tick Always send without asking; later reports are then sent without asking you.

The report includes the error trace, the phone model and OS version, the app version, memory and state data at the time of the crash and a random installation identifier that is not linked to your name or account. It doesn't include your photos. Legal basis: your consent (Article 6(1)(a) GDPR and Article 22.2 of the Spanish LSSI, because the service stores and reads an identifier on your phone). You can withdraw it at any time: by turning off Send crash reports without asking in Settings (the app will ask you again after each crash) or by tapping Don't send when it asks. Retention: 90 days, a period set by Google.

Usage statistics (Google Analytics for Firebase), only if you agree

The first time you reach the home screen, the app asks whether you want to help improve it. Until you agree, the app sends no usage statistics at all. If you agree, we send Google Analytics for Firebase how the app is used: that you started a group photo, took photo A and photo B, whether the merge worked or failed and why, how long it took, whether you saved or shared the result (without saying where), whether you retook photo B, the status of the camera setup (for example, if the phone doesn't support ARCore) and technical data about the phone (camera mode used, megapixels, approximate RAM in ranges and whether you have Step In Pro). With a random instance identifier and another one per attempt, without your name, email, photos or file paths. Google derives an approximate location (country or city) from the IP address, which it doesn't store. It helps us know what fails and what to improve. Legal basis: your consent, which you can withdraw at any time in Settings › Help improve Step In: when you withdraw it, nothing more is sent and the statistics data stored on the phone is deleted. If you don't agree, nothing is sent, not even your answer. We have turned off the advertising identifier and ad personalisation. Retention: 14 months for the data tied to each installation and event. Aggregated reports, which do not identify you, may be kept for longer.

Remote configuration (Firebase Remote Config)

So we can adjust values such as the size of the free photo or the wording of the Pro offer without releasing a new version, the app downloads a small list of settings from Firebase Remote Config. It sends none of your data or photos; Google sees the request like any other connection (IP address and a random installation identifier). Without a connection the app works with its default settings. This request is made when you open the app, without waiting for any prompt, because the app cannot show the offer and its limits properly without it. Legal basis: our legitimate interest (Article 6(1)(f) GDPR) in adjusting and maintaining the service you asked for; we do not use it for statistics or to identify you. Retention: the installation identifier is kept while the app is installed; if it is deleted or you uninstall, Google removes the associated data within a maximum of 180 days. You can stop it by uninstalling the app.

7. iPhone waitlist

If you ask on the waitlist section of this website to be notified (by emailing us):

• Data: your email address, the date and the message in which you ask us to notify you (which is the proof of your consent).
• Purpose: to send you an email when Step In is available for iPhone and to count how many people are waiting, to decide when to release it. We won't send you advertising or other newsletters.
• Legal basis: your consent (Article 6(1)(a) GDPR), which you give by writing to us. You can withdraw it at any time by writing to us or with the unsubscribe link in the notification.
• Who stores it: we do, in the support mailbox, which is run by Gmail (Google). We use no forms or external mailing-list services.
• How long: until we tell you the app is on the App Store; we'll delete the list no later than 3 months after that email. If the iPhone version doesn't happen, we'll delete it 24 months after you signed up.

8. If you write to us

If you write to the support email, we use your address and whatever you tell us (for example, your phone model or screenshots) only to reply and solve the problem. Legal basis: our legitimate interest in handling your request. If you send us photos to help us find a bug, we delete them once it's solved. We keep the conversation for up to 12 months after closing it, unless longer is needed because of a claim. Email is handled by Gmail (Google).

9. This website

This website uses no cookies or analytics tools and loads no resources from other websites. It is hosted on Firebase Hosting (Google Ireland Limited, with Google LLC as sub-processor), which logs technical data about visits (such as the IP address) to serve and protect it, under Google's privacy policy. It has no forms: the waitlist works by email (section 7).

10. Purposes, legal bases and retention

ARCore and ML Kit are handled by Google under its own policy, as explained in section 4.

11. Transfers outside the European Economic Area

This website (Firebase Hosting), the support mailbox and the waitlist (Gmail), as well as Crashlytics and Analytics, are Google services. The processor is Google Ireland Limited (Ireland). Google LLC and other companies in its group may process this data in the US as sub-processors, under the EU-US Data Privacy Framework (Google LLC is certified) and the standard contractual clauses included in the Firebase and Google Analytics data processing terms and in Google's terms for Gmail and Hosting.

12. Your rights

You can ask us at any time to access your data, correct it, erase it, object to or restrict its processing, receive it in a portable format and withdraw your consent, without affecting what was done before. Write to support.stepin@gmail.com saying which right you want to exercise; we'll reply within one month. Since we don't have your photos or an account of yours, for anything inside the app it's enough to delete the photos from your gallery or uninstall the app.

Crash reports and usage statistics are tied to a random identifier of your installation, not to your name or email, and we can't tell whose they are. So, under Article 11 GDPR, we aren't required to identify you in order to handle your rights: we can only access, correct or delete that data if you give us that identifier or other information that lets us link it to your installation. If that isn't possible, the data expires on its own when its retention period ends (90 days for crash reports and 14 months for usage statistics).

If you think we haven't handled your data properly, you can complain to the Spanish Data Protection Agency (www.aepd.es) or the authority in your country.

13. Children

The app doesn't ask anyone for personal data, so anyone can use it. To agree to usage statistics, send crash reports, join the waitlist or write to us you must be at least 14 years old (or the minimum age in your country); if you're younger, ask a parent or guardian to do it for you. If you photograph children, take extra care when sharing the photos.

13. Changes to this policy

If we change what the app does with data (for example, if we add crash reports, usage statistics or purchases), we'll update this policy before the version that includes it is released, change the date above and, where the law requires it, ask for your permission in the app.