Opal
iPhone and Mac screen-time rules with hardened app blocking
The visible screen-time control loop is buildable, but a credible replacement needs more than the first screen. Opal earns its keep through polish, OS integration, so expect a weekend or multi-day build and a narrower personal scope.
Build verification: not recorded. How we judge buildability
What you give up
- cross-device sync
- deep operating-system edge-case coverage
- polished shortcuts and accessibility
- vendor-maintained updates
Why people still pay
Opal: People keep paying because a utility used dozens of times a day must be instant, predictable, and compatible with every OS update.
Your build guide
The stack, security requirements, and agent rules for a focused replacement.
Before you start
- Runtime and tools: Swift, SwiftUI/AppKit and SQLite on macOS, with secrets in Keychain where needed.
- Before starting: A Mac, the current Xcode toolchain and a documented permission checklist; distribution signing is a separate delivery task.
Use these project rules and optional skill references alongside the prompt. Review each skill before adding it to your agent; the AGENTS.md export includes the same guidance.
Project rule — domain: Store FocusPlan, AppSelection, Session, Override and PermissionState; intentional overrides are recorded and loss of permission cannot be shown as successful enforcement.
Project rule — scope and recovery: Scope to one desktop platform and documented permissions. Do not claim unbreakable iPhone Screen Time controls or prevent access to emergency/system functions.
Project rule — acceptance: Revoke a blocking permission during a session and restart the app; display degraded enforcement, preserve the session clock and offer a clear stop/unblock path.
Project rule — delivery: document real setup commands and permissions; do not claim a build, accuracy level, performance result or security certification that has not been demonstrated.
Recommended skill: swiftui-expert-skill — design native SwiftUI state, accessible controls and permission/error views for the proposed Apple-platform interface. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Recommended skill: swift-concurrency — isolate capture, background work and UI updates, and make cancellation invalidate late callbacks. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Implementation plan
Phase 1
Pin the working slice and create its example input: Plan a focus interval, list selected distracting apps and show an accountable local timer with optional supported blocking controls. Confirm setup: A Mac, the current Xcode toolchain and a documented permission checklist; distribution signing is a separate delivery task.
Phase 2
Implement persistence and write-time invariants before decorating the UI: Store FocusPlan, AppSelection, Session, Override and PermissionState; intentional overrides are recorded and loss of permission cannot be shown as successful enforcement.
Phase 3
Connect the working view to real saved state. Ask for each operating-system permission when its feature is used. Handle denial and revocation without a loop; show permission status and keep local history deletable.
Phase 4
Expose the app-specific limits and recovery path in context: Scope to one desktop platform and documented permissions. Do not claim unbreakable iPhone Screen Time controls or prevent access to emergency/system functions.
Phase 5
Walk through this concrete acceptance case and preserve its exported evidence: Revoke a blocking permission during a session and restart the app; display degraded enforcement, preserve the session clock and offer a clear stop/unblock path. Finish the README and backup/restore instructions; report unfinished capabilities explicitly.
Build the following focused alternative to Opal. This is a deliberately limited personal or small-team substitute, not parity with the paid service. WORKING SLICE Plan a focus interval, list selected distracting apps and show an accountable local timer with optional supported blocking controls. SETUP AND ARCHITECTURE Use Swift, SwiftUI/AppKit and SQLite on macOS, with secrets in Keychain where needed. Prerequisites: A Mac, the current Xcode toolchain and a documented permission checklist; distribution signing is a separate delivery task. Before integrating anything, record actual versions and permissions, plus model files or provider limits only where used, in the README; make unavailable dependencies visible rather than simulating success. DOMAIN MODEL AND INVARIANTS Store FocusPlan, AppSelection, Session, Override and PermissionState; intentional overrides are recorded and loss of permission cannot be shown as successful enforcement. IMPLEMENTATION CONTRACT Ask for each operating-system permission when its feature is used. Handle denial and revocation without a loop; show permission status and keep local history deletable. Provide an input/setup view, the main work view, and a review/export view appropriate to this workflow. Preserve the last saved state if a job or save fails. Include empty, loading, permission-denied, partial and retryable-error states. Log identifiers and error categories without secret values or unnecessary private content. APP-SPECIFIC BOUNDARY AND RECOVERY Scope to one desktop platform and documented permissions. Do not claim unbreakable iPhone Screen Time controls or prevent access to emergency/system functions. ACCEPTANCE SCENARIO Revoke a blocking permission during a session and restart the app; display degraded enforcement, preserve the session clock and offer a clear stop/unblock path. Also reopen the app after an interrupted operation, confirm the saved record/export remains inspectable, and document the recovery action. These are implementation acceptance requirements, not a claim that this guide has been tested. DELIVERY Deliver a runnable repository with migrations or project-format versioning, a non-sensitive example, environment/permission setup, the exact manual acceptance steps, and a backup/export-and-restore walkthrough. Implement the working slice before optional integrations; list any deferred paid-product capabilities honestly. Do not add capabilities outside the working slice just to resemble the original product. PROJECT RULES FOR AGENTS.md Keep the domain invariants above executable at the write boundary. Propose scope changes before adding providers or permissions. Never fabricate source evidence, publish results, identity matches or successful delivery. Preserve user originals and require an explicit confirmation for destructive changes or external publication.
$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy or download AGENTS.md · generated from this app's build plan
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Opal pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| free | $0/user | $0/user | 1 blocking rule; basic timers and soundscapes; Screen Time Score limited to today. |
| pro | $19.99/user | $8.33/user | Unlimited blocking rules and the full Pro feature set.The yearly option is $99.99/year with a 1-week trial. The page's 'Monthly' panel says $19.99/month with a 3-day trial but also says '$239 billed annually,' so its actual billing cadence is internally inconsistent. |
| pro lifetime | — | — | Lifetime Pro access.One-time $399. |
| teams | — | — | Custom team administration and deployment; no public price or numeric limits.Contact sales. |
free tier1 blocking rule; basic timers and soundscapes; Screen Time Score shows today only.
billingannual + lifetime; a $19.99 'Monthly' option is displayed, but the same official panel says $239 billed annually
hidden costsStudent pricing is up to 50% off. Direct Stripe purchases have a 30-day refund policy, while Opal cannot refund Apple-billed purchases. The public monthly-panel billing copy is contradictory.
pricing sources checked 2026-08-14 · pricing source ↗
Questions about Opal
Can you build your own Opal with AI?
Partly. The visible screen-time control loop is buildable, but a credible replacement needs more than the first screen. Opal earns its keep through polish, OS integration, so expect a weekend or multi-day build and a narrower personal scope.
What does the Opal build prompt cover?
The prompt starts with this scope: Plan a focus interval, list selected distracting apps and show an accountable local timer with optional supported blocking controls. Full-product capabilities excluded from the comparison include: cross-device sync; deep operating-system edge-case coverage; polished shortcuts and accessibility. Follow the implementation plan and its prerequisites before expanding the build.
How do I use the prompt, AGENTS.md and agent skills?
Start with the Opal prerequisites and stack, then copy the prompt into your coding agent. Save the project rules as AGENTS.md in the project root. Linked skills are optional packages or source instructions for specific tasks; review their current contents and install only those matching the chosen stack. A skill does not supply API credentials or verify the finished app.
How long will this Opal project take?
The catalogue estimate is multi-day for the limited scope. Setup, integration approvals, debugging, deployment and ongoing maintenance can add time. This is an estimate, not a delivery guarantee.
What would I give up by replacing Opal?
cross-device sync; deep operating-system edge-case coverage; polished shortcuts and accessibility; vendor-maintained updates. Opal: People keep paying because a utility used dozens of times a day must be instant, predictable, and compatible with every OS update.
What price is this guide comparing against?
The recorded Pro plan is $8.33/mo (annual-equivalent individual subscription), checked 2026-07-31. Check the linked pricing source before buying. Building your own also has hosting, API and maintenance costs; the recorded amount is not a guaranteed saving.
What can I use instead of building Opal?
Apple Screen Time: Built-in Apple limits with passcodes and device sync; less stubborn, but genuinely free. ScreenZen: The hardened blocker without the subscription: delays, limits, strict sessions, and cross-device apps. Check each option's license, hosting needs and feature limits.