# Automated iPhone Duo compatibility testing

Source: https://foldready.dev/foldcheck

Published: 2026-09-12. Updated: 2026-09-12. Author: FoldReady (vity5.diduk@gmail.com).

Summary: FoldCheck is an automated compatibility tester for iPhone Duo: upload a simulator build, it drives the app through all 6 poses (closed, open and half folded, each in portrait and landscape) plus side-by-side multitasking, reports clipped, stretched and colliding layouts per view, and suggests the code change.

## How FoldCheck works

1. **Upload a build.** Point FoldCheck at a simulator build or a TestFlight archive.
2. **Every pose, every screen.** It drives the app through all 6 poses (closed, open and half folded, each in portrait and landscape), plus side-by-side multitasking and both size classes.
3. **Issues, not screenshots.** Clipped text, hardcoded widths, overlapping system UI and missing size-class handling are flagged with the offending view.
4. **Fixes you can merge.** Each finding comes with a suggested SwiftUI or UIKit change and a before/after screenshot.

## What FoldCheck detects

- Clipped or truncated content
- Hardcoded frame widths and heights
- UIScreen.main.bounds usage
- Missing regular-width layouts
- Custom bars colliding with system UI
- Content straddling the fold crease
- State loss on outer-to-inner handoff
- Broken multi-window resizing

## Demo video

A FoldCheck run from start to finish: a build is uploaded, the app is shown in every iPhone Duo pose, three layout findings are listed, an AI fix adapts the layout, and a PDF report and video are produced. 30 seconds, 1920x1080: https://foldready.dev/demo/foldcheck-v1.mp4

## Early access

FoldCheck is in early access and free for the first apps on the list. Email vity5.diduk@gmail.com with the subject "FoldCheck early access" to have your build run.