We make an alarm app, and this page is written to be useful even if you never install it. The free fixes come first, because for most people they are enough. Anything about sleep itself is sourced to published research or the NHS rather than to us, and linked at the bottom. Mornio is not a medical product and cannot diagnose or treat anything.
Short answer
Three sections, in descending order of importance. Data Used to Track You means linked to third-party data for advertising or shared with brokers. Data Linked to You means tied to your identity. Data Not Linked to You means collected but not identifying.
Read the first one first, then tap See Details and look for Third-Party Advertising as a purpose. Remember these are developer declarations, not audits.
Apple's privacy labels are genuinely useful and almost nobody reads them properly. Two minutes of knowing what the sections mean will tell you more about an app than any review will.
Where to find it
On any App Store listing, scroll down to App Privacy. You will see a summary; tap See Details for the full breakdown by data type and purpose. That second screen is where the useful information lives.
The three sections
1. Data Used to Track You
The one that matters most. Apple defines tracking specifically: linking data with third-party data for targeted advertising, or sharing it with a data broker. It is narrower than “collects data”, which makes anything listed here a meaningful statement rather than a vague one.
Seeing Location here in an app with no location-based feature is worth pausing over.
2. Data Linked to You
Collected and tied to your identity, usually via an account. Not necessarily used for advertising, but attributable to you specifically. An app requiring sign-up will almost always have entries here.
Some are unavoidable given what the app does. Nuj lists financial info because it charges penalties; Sleep Cycle lists health data because it analyses sleep. Ask whether the data is necessary for the feature you actually want.
3. Data Not Linked to You
Collected but not attributed to your identity, typically aggregate analytics and crash reports. Usually the least concerning, and most well-behaved apps have something here.
The purposes worth checking
On the See Details screen, each data type lists why it is collected:
Third-Party Advertising. The one to watch. It means your data is feeding an advertising ecosystem beyond the developer.
Developer's Advertising or Marketing. Lighter. The developer marketing their own products.
Analytics. Usually benign, understanding how the app is used.
App Functionality. Needed to make the thing work.
Product Personalisation. Tailoring what you see.
Do not forget the age rating box
Separate from App Privacy, and easy to miss: the information section can carry “Contains Advertising”. That is Apple's flag for an ad-supported app, and it is a fast way to know what you are getting into. A “Remove Ads” in-app purchase tells you the same thing.
What labels cannot tell you
Being honest about the limits, because over-trusting them is its own mistake:
They are self-declared, not audited. Apple can act on misdeclarations, but the label is the developer's statement, including ours.
They change between versions, so a label you checked last year may not hold.
They do not show volume or retention. “Usage Data” could mean very little or a great deal.
They say nothing about security, only about collection.
A change of developer can change everything, and this is the one people miss. An app sold to a new owner can adopt an entirely different data posture with the same name and icon.
A two-minute routine
Read Data Used to Track You. Anything surprising?
Tap See Details and scan for Third-Party Advertising.
Check the age rating box for Contains Advertising.
Check whether an account is required, and ask what the app needs one for.
After installing, check Settings → Privacy & Security → App Privacy Report for what it actually does.
Apple defines it as data linked with third-party data for targeted advertising, or shared with a data broker. It is narrower than collecting data in general, which makes anything listed there a specific and meaningful statement. It is the section worth reading first.
What is the difference between Data Linked to You and Data Not Linked to You?
Linked means the data is tied to your identity, usually via an account, so it can be attributed to you specifically. Not linked means it is collected without that attribution, typically aggregate analytics and crash reports. Linked data is not automatically bad; some is unavoidable for what the app does.
Are App Store privacy labels reliable?
They are self-declared by developers rather than independently audited, so treat them as statements rather than proof. Apple can act on misdeclarations, which gives them some weight. They also change between versions and say nothing about data volume, retention or security, so they are a starting point rather than a full picture.
How can I see what an app actually does after installing it?
Go to Settings, Privacy and Security, and turn on App Privacy Report. It records which sensors and data an app accesses and which domains it contacts, which is a useful reality check against the declared label. Also review Settings, Privacy and Security, Tracking to control which apps may request tracking permission.
Sources
Alarmy’s App Store listing carries Apple’s “Contains Advertising” note in its age-rating information, and its App Privacy section lists Third-Party Advertising as a stated purpose for Location (precise and coarse), Device ID and Advertising Data. Its description also states “Free features: alarm clock, sleep tracker, sleep sounds etc.” and that a 7-day free trial is provided. App Store listing.
Mornio Privacy Policy, on what is stored on your iPhone and what is not stored at all.
Sleep Cycle - Tracker & Sounds, Sleep Cycle AB. App Store listing (features, compatibility and App Privacy labels).
Erly: Wake Up Early, Glacier Labs LLC. App Store listing (compatibility, feature description and App Privacy labels).
App Store details change without notice. Everything above was checked on 21 July 2026 — if you spot something out of date, tell us at support@mornioapp.com and we’ll correct it. Written and published by the Mornio team. Last reviewed 21 July 2026.