Articles

Core Bluetooth

Why Core Bluetooth state restoration never fires21 September 2026Setting a restoration identifier is only the first step. What else your app has to do, when the system will and will not relaunch it, and how to test it without fooling yourself.

How an iOS app extension talks to its containing app19 October 2026For most extensions the answer is that it can't, because the app usually isn't running. What works is writing to the App Group container and letting the app read it when it runs. How to do that properly, the few exceptions, and why you may not need any of it.

Why an NFC reader session has a time limit21 September 2026There is no continuous NFC mode on iOS. A reader session is a short, user-visible burst with a fixed lifetime, and every way of pretending otherwise makes the app worse.

Trust Insights, or how your app can tell when someone is being talked through a scam2 November 2026iOS 27 can tell a bank app when it looks like the person confirming a transfer is being coached by someone else. What it tells you, the app code step by step, and what nobody can test yet.
App Attest, or how you can trust an app that cannot keep a secret27 October 2026An API key in your app is not a secret; anyone with the binary can read it. Keep secrets on the server, and use App Attest so the server can tell your real app from everything else. The app side, the server checks, and the things that trip people up.

A SensorKit fetch that returns nothing is usually asking for the wrong window22 September 2026A fetch cannot reach earlier than your app's authorization or later than 24 hours ago, and a range that breaks either rule returns no samples and no error.