Acuo

Privacy policy

This policy describes what the Acuo app and its server collect, why, where it is kept and how to have it deleted. It describes what the code actually sends, not what we would like it to send.

Draft. This text has not yet been accepted and may change before the app is released. Version of 28 September 2026.

Who is responsible

Acuo is developed by (to be named before the app is released). Questions about your data: (the address will be published here before the app is released).

What the app sends and why

The app sends data only to our own server. It works offline and sends what it has collected once you are back online.

Game results. For every answer in a game: the time it took, where and how you touched the screen (including the path of your finger), whether the answer was correct, interruptions such as leaving the app mid-game, the interface language, whether power saving was on and which audio output was in use (speaker, headphones, hearing aid). Why: to adapt the games to you and to compute a measurement estimate with its range. Raw answers are kept as they are, so an estimate can be recalculated later without losing information.

Device profile. Manufacturer, model, operating system and its version, screen size and density, refresh rate, the app build and your time zone offset from UTC. Why: reaction times depend on the phone, and results from different phones can only be compared when the phone is known.

Install identifiers. On first launch the app creates random identifiers for you and for this install, and a secret that proves later requests come from the same install. The server keeps only a hash of the secret. These identifiers are not your name, email or phone number.

Account (optional). You can play without an account. If you sign in, we keep your email address or, with Google sign-in, the identifier Google gives us for your account. With Google sign-in the app asks Google only to confirm who you are and does not request access to any other Google data. To sign in by email we send a one-time code to your address.

Reminders (only if you turn them on). When a reminder was scheduled, shown and opened. Why: to find out whether reminders help people come back, rather than assume it.

Promo codes. Which code you redeemed and what access it gave.

Crash reports. When the app fails, it sends the error message and technical trace, the app version, the phone model and the operating system version. Crash reports carry no user or install identifier. A daily summary of crashes is emailed to the developer.

Network address. Our server sees the IP address of each connection. It is used, in memory only, to limit the number of requests from one address, and is not written to our database. The web server keeps no access log.

What we don’t do

Other services involved

Where and how long data is kept

The server and database are in Germany. Game results, device profiles and account data are kept for as long as your account or install exists, because an estimate is recalculated from the raw answers. There is no automatic deletion yet. Crash reports carry no identifiers and are kept to fix errors.

The database is backed up every hour. Backups are encrypted before they leave the database, a copy is kept outside the server, and each backup is kept for up to 14 days. Data deleted at your request therefore disappears from backups within 14 days.

Your rights

You can ask for a copy of your data, for it to be corrected or deleted, and object to its use: write to (the address will be published here before the app is released). We answer within one month. If you live in the EU, you can also complain to your data protection authority.

How to delete your account and data is described on the Delete account page.

Changes

When this policy changes, the new version appears on this page with a new date.