Two of the most well-known indie screen-time apps in 2026 — one VC-funded and polished (Opal), one bootstrapped and peer-reviewed (One Sec). They share a category and almost nothing else. Here is the side-by-side, with the third option Muslim users should know about at the end.
| Feature | Opal | One Sec |
|---|---|---|
| Gate mechanism | Scheduled blocks + sessions | Per-open deep breath |
| Time per unlock | Wait out timer / break session | 1–3 seconds (configurable) |
| Price | $69.99/yr Pro | $24.99/yr Pro |
| Free tier | Limited | Limited apps |
| Peer-reviewed evidence | No | Max Planck, Heidelberg, 57% reduction |
| Funding model | VC-backed, $10M ARR | Bootstrapped, indie |
| Family plan / parental | Yes | No |
| Behavioural tracking | Productivity scoring | Opt-in |
| Available on Android | Yes | Yes |
| Founded | 2020 | 2021 |
Opal is better for users who want family plans, deep iOS Screen Time integration, and a polished productivity dashboard — and accept the $69.99/yr cost. One Sec is better for users who want a single-mechanism, evidence-backed per-open gate at $24.99/yr. For Muslim users, the third option — HalalScreen — uses the One Sec mechanic family but anchors the gate in dhikr instead of breath, and it is free with no subscription.
Only if you need what Opal does and One Sec does not — family plans, productivity scoring, deeper iOS Screen Time integration. If your job-to-be-done is the per-open gate alone, One Sec does that at half the price with peer-reviewed evidence behind it. The honest answer is: Opal is the bundle, One Sec is the mechanism.
Not directly. One Sec's peer-reviewed studies (Max Planck, Heidelberg) are specifically of its single-mechanism deep-breath gate. Opal's scheduled-block model is mechanically different and has not been independently studied at the same level. Opal may work for its users; the evidence base is just thinner.
Technically yes, but the two products would overlap on most distracting apps. A cleaner setup is one primary tool — Opal for users who want the full productivity bundle, One Sec for users who want the gate mechanic alone. Stacking single-mechanism gates and scheduled blocks usually leads to disabling one within two weeks.
Yes — HalalScreen is the closest Muslim equivalent. It uses a single-mechanism per-open gate (mechanically similar to One Sec) but the gate is the Sunnah dhikr count (33 SubhanAllah) instead of a breath. It is free, bootstrapped, and built specifically for Muslims who want their screen-time tool to sit inside the language of deen rather than the language of productivity.
Want to see how your scroll time converts to dhikr?
The scroll-to-dhikr calculator does the math.
Free on the App Store. No in-app purchases, no subscription, no tracking. Thirty seconds of counted dhikr — the Sunnah-prescribed 33-33-34 — between you and the apps that pull you in.