Dumb phone (Focus mode): finish it, or rebuild it

[jsconu]

A plain home screen keeping only calls, texts, sign-in codes and a short list of allowed apps — with a Travel profile for adults and an "All apps" escape hatch after a pause. It is written and it is switched off, because it isn't good enough to put in front of a family.

It ships disabled via a single constant, Features.DUMB_PHONE, rather than deleted. Whoever takes this on starts from working code and a considered design instead of an empty file.

Why it's off

Replacing a phone's home screen touches three things at once — the launcher role, the foreground guard, and the app list — and getting it wrong leaves someone holding a phone that won't open anything. That's a bad failure for a tool a family depends on, and a worse one for a child.

While the flag is false: nothing offers it, the phone never asks to become the home app, the launcher activity stays disabled in the manifest, and a focusMode flag arriving from a parent's phone is ignored rather than enforced (FocusDevice.sync).

What's already there

• FocusMode, FocusConfig, isFocusAllowed, focusHomePackages — the rules about what stays reachable
• FocusHome, FocusLauncherScreen — the home screen itself
• FocusDevice — the launcher role, the saved state, and the "open for 10 minutes" window
• FocusModeSection — the parent-facing settings, in both apps
• Profile fields: focusMode, focusProfile, focusAllowedPackages, travelAllowedPackages

What finishing it probably means

• Real devices, several makes. This is where it breaks: launcher behaviour varies a lot, and an emulator won't tell you.
• A way out that always works, including when the app crashes or is force-stopped — a phone must never be bricked into a home screen that won't load.
• Deciding what happens on reboot, on update, and when the app loses the launcher role.
• Whether a child should be able to leave it at all without a parent's passcode, and what happens in an emergency.
• The ideas the README used to list: schedules, per-contact rules, richer profiles, an e-ink friendly layout.

Before starting

Please open a comment here with the approach you want to take — this is the kind of change worth agreeing before anyone writes code. CONTEXT.md has the domain language and CONTRIBUTING.md the code map. Keep to the project's design line: calm, plain, and never a hook.

[jsconu]

One concrete, self-contained piece for whoever picks this up — it was drafted as a standalone starter task before dumb phone moved here, and it's the smallest useful thing in the feature:

Grey out apps that are blocked right now, on the dumb-phone home screen

The "All apps" list shows everything the same way, so a child taps an app that's currently blocked — daily limit reached, bedtime, a parent lock, or simply not on the allowed list — and gets bounced with no explanation.

Grey it out in the list, and on tap say plainly why it isn't available instead of launching it and sending them home a second later. The reason already exists: decideEnforcement is a pure function that returns it, so this is about surfacing what the code already knows.

Where: shared-ui/src/main/java/org/openscreentime/sharedui/FocusHome.kt and FocusLauncherScreen.kt. CONTEXT.md defines the terms.

Note: this only applies to our own home screen — Android doesn't let one app grey out icons in someone else's launcher.

Done when: a blocked app is visibly distinct and tapping it explains why, in language a nine-year-old would understand. Keep it calm — no red, no scolding.

Worth doing early if you take this on: it's small, it's visible, and it exercises the launcher screen without touching the launcher role, which is the risky part.