How AI interview assistants capture system audio on iOS, and why they mostly cannot

A desktop interview assistant works because desktop operating systems expose the audio another application is playing. On macOS that door is ScreenCaptureKit, the same permission family that powers screen recording; on Windows it is WASAPI loopback, which lets a process read the system output mix. SubcueAI's dual audio capture is built directly on those two APIs.

iOS has no public equivalent. Each app runs in a sandbox with its own audio session, and the system does not offer third-party apps a loopback channel into the mix or into another app's session. A Zoom call running on an iPhone is audible to Zoom and to the speaker, not to a different app installed on the same phone. This is a deliberate platform decision, and it has held across iOS releases.

The consequence is blunt: the desktop assistant architecture, capture system audio, transcribe it in real time, surface suggestions, cannot be ported to iOS as-is. Any product that claims otherwise is doing something materially different under the hood, and it is fair to ask vendors exactly which API they use.

If your interview has to happen on an iPhone, you are right that the options feel thin, and it helps to know precisely what each workaround can and cannot do. There are three patterns in circulation, and each trades away something important.

• ReplayKit broadcasts. iOS can record the screen with app audio through a user-initiated broadcast, but the stream runs inside a tightly constrained broadcast extension. It is built for streaming a screen to services, not for feeding a second app that analyzes call audio and answers in real time.
• Speakerphone plus a second device. Put the call on speaker and let a laptop's microphone listen acoustically. This works with any assistant, including SubcueAI's microphone channel, but room echo and crosstalk cut transcription accuracy, and the interviewer hears you in a speakerphone acoustic.
• Employer-side integrations. Some interview platforms transcribe calls server-side for the company. That is the employer's tooling on their infrastructure; it does nothing for the candidate's side of the table.

None of these reproduces the desktop experience. The honest summary is that a phone-only interview leaves real-time assistance out of reach, and preparation beforehand carries the weight instead; a mock interview session the night before does more for a phone screen than any workaround during it.

SubcueAI ships native desktop apps for macOS 14 and later and Windows 10 and later, and deliberately does not ship an iOS app. Aaron Cao, founder of SubcueAI, has been direct about the reasoning: an iPhone app could not perform the product's core function honestly, and shipping a degraded listener that pretends otherwise would trade user trust for an App Store listing.

The practical recommendation follows from the architecture. Take video interviews on a computer whenever the choice exists; recruiters almost always offer a desktop join link for Zoom, Google Meet, and Microsoft Teams calls. On the desktop, the assistant hears the call through the operating system rather than through the air, and the setup tutorial walks through permissions for both platforms in a few minutes.

For the parts of interview preparation that do fit a browser, including the AI mock interview, a phone or tablet works fine, because practice does not require capturing another app's audio. The architecture details behind the desktop capture path are collected in the how-it-works answers.