Color Vision Plates vs App Lock

I'm colorblind. Every "color blind test" app I tried was either a marketing funnel, an ad farm, or scientifically wrong. So I built the one I wanted: real methodology, sources cited, nothing to sign up for. Color Vision Plates is a 14-plate screening for red-green and blue-yellow color vision deficiency. It doesn't just say "you're colorblind." It attempts to classify the type: protan (red-weak), deutan (green-weak), or tritan (blue-yellow), using dedicated classifier plates that vanish for one type but not the other. HOW IT WORKS • Ishihara-style number plates and HRR-style shape plates (the two standard clinical methodologies, in use since 1917 and 1954) • Classifier plate colors generated by simulating dichromatic vision with the Brettel-Viénot-Mollon (1997) model and selecting pairs that survive one deficiency and disappear under the other • All plate colors defined in CIELAB with matched luminance, so hue is the only available cue: no brightness leaks to give the figure away • A display calibration check before the test starts, because a dimmed or Night-Shifted screen produces false positives • A control plate that catches display problems and flags the result as inconclusive instead of guessing • Plate order shuffles and dot patterns reroll on every retake, so you can't memorize an answer key WHAT YOU GET • A plain-English result ("Likely Green-Type Color Difference") with the clinical term alongside for your eye doctor • What the result might mean day-to-day: brake lights, status indicators, charts, ripe fruit • A plate-by-plate review of every answer • Screening history saved on your device, so you can retest over time and compare honestly • The methodology and full citations, one tap away, always THE HONEST PART This is a screening, not a medical diagnosis. Phone screens vary; clinical tests use calibrated printed plates under standardized lighting. The app says this everywhere (before the test, on your results, in your history) because a screening tool that oversells itself is worse than none. If your results suggest a color vision difference, see an eye care professional. PRIVACY No accounts. No tracking. No analytics. No ads. No network calls. The entire test is bundled with the app and runs offline. Your results stay on your device, and you can erase them anytime. THE SCIENCE Ishihara (1917); Hardy, Rand & Rittler (1954); Brettel, Viénot & Mollon (1997); Sharma, Wu & Dalal (2005) for CIEDE2000 color difference; Birch (2012) on prevalence. From the maker of What Color Is This?, the camera color-identifier built for colorblind people. About 1 in 12 men and 1 in 200 women have a color vision difference. Most found out by accident. This is a better way. Made by Luke Steuber. Published by Bridge City Lab LLC.

Lock the apps you do not want others to open. Lockstead helps you restrict selected apps on your own iPhone or iPad using Apple Screen Time. Choose apps to block, enable protection, or set weekdays and times for restrictions. Protect access to Lockstead settings with your six-digit PIN and optional Face ID or Touch ID. VIP GUEST MODE Choose specific apps, select a duration from 15 minutes to 12 hours, and confirm the session. Lockstead applies an allowlist to supported apps through Screen Time. Try opening an allowed app and a restricted app before handing over your device. CHOOSE, APPLY, CHECK Block selected apps, set protection schedules, or temporarily allow access. Guest Mode takes priority over normal lock and temporary-access rules. When it ends, Lockstead reapplies the rules for that time; it does not simply unlock everything. iOS background scheduling can delay changes. FOR EVERYDAY HANDOFFS Let a friend use a map or lend your iPad for reading, with the apps needed for that session. Content inside allowed apps remains accessible. Guest Mode does not create a separate user account or separate app data. FREE CORE, OPTIONAL VIP Core protection for one selected app is free. VIP adds multi-app management, Guest Mode, advanced rules, app-removal controls, themes and alternate icons. Choose a monthly or yearly auto-renewing subscription, or a one-time lifetime VIP purchase. Prices are shown by your regional App Store. SETTINGS ON YOUR DEVICE Protect access to Lockstead with a six-digit PIN and optional Face ID or Touch ID. No app account, developer backend, advertising SDK or analytics SDK. Protection settings stay on your device; purchases use Apple services. Requires iOS/iPadOS 17 or later and Screen Time authorization. Availability and enforcement depend on iOS. Restrictions do not encrypt files, guarantee hidden icons or suppress notifications. This is not remote device management. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://materialofair.github.io/lockstead-site/privacy.html