tl;dr: GrapheneOS has released version 13 of its Messages app, a full rewrite using Jetpack Compose and Material 3 that rebuilds every screen and adds large-screen two-pane layouts, conversation pinning/snoozing/archiving, a redesigned media picker and share flow, and improved onboarding. The update hardens privacy and security with opt-in YouTube previews, stricter shared-content and content-URI validation, immutable pending intents, non-exported widget receivers, and allocation limits on EXIF/MMS parsing, alongside numerous crash, notification, sync, and accessibility fixes. It targets SDK 37 (minSdk 36) and pulls in Compose BOM, CameraX, Coil 3, and Navigation 3.