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Sparky vs Habit Doom: Photo Proof or Trust, Which Fits You

August 2, 2026 · updated October 7, 2026

I build Sparky, so read this knowing where my stake is. Habit Doom is the closest app to ours. Both lock your feeds until you finish real habits, and the choice comes down to one question about you: do you want a camera to check your check-ins? If yes, pick Habit Doom. If being checked would make you quit, pick Sparky.

Every Habit Doom fact below comes from its App Store listing, its site or its own blog, checked 4 October 2026. Every Sparky fact comes from version 1.6 (build 30), the build on the App Store that day.

What do Sparky and Habit Doom do the same way?

Sparky and Habit Doom run the same loop. You pick the apps that cost you the most, the app locks them with Apple’s Screen Time framework, and finished habits earn minutes inside them. Both are free to start, both run on iPhone and iPad, and both stop locking the moment you remove the Screen Time permission.

Neither is a workaround of iOS. Both use FamilyControls and ManagedSettings, so both inherit the same ceiling. Apple’s own Screen Time does the lock half for free, with no earning at all, and if a plain daily limit works for you, you need neither of us. Most people reading this have tapped “Ignore Limit” too many times for that to be true. Both apps also sit in a wider field, which we map in our guide to apps that make you earn screen time.

How does Habit Doom’s anti-cheat work?

Habit Doom’s answer to cheating is a camera. With Anti-Cheat Mode on for a habit, checking in opens the camera, and same-day check-ins need a live photo, not one from your camera roll. An on-device model judges the photo, and a clear match verifies in well under a second. Anti-Cheat is opt-in per habit.

Habit Doom gives Anti-Cheat away. Its free tier allows 3 active habits and includes the photo check, so nobody has to pay to be checked. Borderline photos get a sheet with three choices: stand by it, retake it, or cancel.

Credit where due: Habit Doom’s own write-up, dated 6 June 2026, is honest about the costs. Running the model locally “costs about 145 MB of app size”, and the first check after a fresh launch takes a couple of seconds while the model warms up. Photos never leave the phone. The post also admits what most marketing pages would hide: “A determined cheater can stand by a photo of their ceiling.” Its override sheet warns that “An inaccurate photo will poison future check-ins,” because the model learns from what you let through.

Habit Doom also added Hard Mode after our first version of this page. With it on, you “Can’t undo check-ins, delete habits, or remove apps,” says the listing. Sparky 1.6 has nothing like it.

Why does Sparky not verify photos?

Sparky skips photo checks because the failure we designed against is quitting, not cheating. A camera step on every glass of water adds friction to your best behavior, not your worst. Our bet is that a person who fakes a check-in to open TikTok has told themselves something out loud, and that moment of self-report is the real intervention.

Friction does work. The PNAS study of one sec followed 280 people for six weeks. They closed the target app in 36 percent of attempts after a short pause appeared. One of its authors, Frederik Riedel, created one sec, the app it studied, and the paper discloses that. But friction stacks. We would rather spend it on the reach for TikTok than on the glass of water.

That bet has a real cost. Sparky’s numbers are only as true as you are. If you know you will tap check-ins you did not do, and you know a camera would stop you, Habit Doom fits you better and you should use it.

Why do Screen Time apps act strangely at midnight?

Apple explained the core of it in March 2023. In forum thread 726331, an Apple Frameworks Engineer wrote that adding a day component to a schedule’s end makes iOS treat the schedule as already running. iOS then counts usage from before you started, and the threshold fires at once. Midnight is where that mistake is easiest to make.

The engineer’s example was a Monday at 1:00 p.m. With .day in the end components, iOS decided the schedule had started on Sunday and would end that afternoon, so it “will include all app usage that occurred between those two dates.” The fix was to drop .day and keep the start and end components consistent. The thread is “DeviceMonitoringActivity - 10 minute threshold instantly breached”.

A second thread, 729841 from May 2023, reached the same rule by trial and error. Its author tried four mixes of date and time components and concluded: “So it seems that the correct and working version is with the time components only.” The thread collected 6 replies through March 2025. No Apple engineer answered it.

Put those rules together and you get the midnight trap. A schedule built from time-only parts cannot cross midnight, because 23:50 to 00:05 reads as an end before a start. DeviceActivity also rejects any window under 15 minutes (intervalTooShort). Start a short unlock at 12:08 a.m. and clamp it to midnight. The window is now under 15 minutes, and iOS refuses it with “the activity’s schedule is too short.”

How do Sparky and Habit Doom handle midnight?

Habit Doom sidesteps most of it. Its homepage says “Every midnight at 11:59 PM, your chosen apps lock automatically,” one minute before the date changes. A lock at 23:59 never has to carry an open session across midnight. Sparky banks unused minutes instead, so its relock code has to cross that line, and it does so carefully.

I do not know why Habit Doom picked 11:59 rather than 12:00. I have never seen its code. I can show you ours. In Sparky 1.6 the relock code lives in AccessWindowMonitorScheduler.swift, and one comment there reads, in capitals, “NEVER add day-bearing components to either endpoint”, with both thread numbers beside it. The same comment block credits a Screen Time guide on habitdoom.com.

When a Sparky session crosses midnight, the code moves the schedule’s start to 00:00 on the relock day. If that leaves under 15 minutes, it pads the monitor to 15 minutes and relocks from a warning callback at the true end. An early build missed that second case. The refusal failed the whole session start and left gated apps unreachable at the exact moment the user had earned them.

The same file records a change from 14 June 2026. Sparky stopped using a usage threshold for its relock and moved to the wall-clock end of a schedule. On iOS 26, three sessions relocked about 2 seconds after their end, per the note in that file. The iOS 26 bug that pushed us there, and what helps, is in why app blocker limits fire instantly on iOS 26.

So when an earn-your-screen-time app relocks a minute late, or seems to reset at 12:00, this API is the usual reason. The two apps answer it differently on purpose. Habit Doom’s daily relock is a clean rule that is easy to trust. Sparky’s bank keeps minutes you earned on Tuesday for Wednesday. The price is fussier midnight code.

What do Sparky and Habit Doom cost in October 2026?

Habit Doom is free for 3 active habits, Anti-Cheat included. Its Pro plan costs $4.99 a month with a 7-day free trial, $19.99 a year or $29.99 for life, per habitdoom.com on 4 October 2026. Sparky is free for 5 active habits, and Sparky Pro lists at $8.99 a month, $59.99 a year or $129.99 for life.

Habit Doom is cheaper at every tier. Its lifetime price is less than a quarter of ours. It also reaches older phones: Habit Doom needs iOS 17.6, and Sparky needs iOS 26.0.

Size runs the other way. Habit Doom 2.22 is 171.9 MB on the App Store, and its blog puts about 145 MB of that down to the local model. Sparky 1.6 is 59.9 MB. Habit Doom shipped 12 versions between 14 August and 3 October 2026, by its version history, and it shows 4.85 stars from 20 ratings. Sparky still shows no rating at all.

Privacy labels favor Habit Doom too. Its label declares no tracking and lists usage data collected for analytics, not linked to you. Sparky’s label declares tracking of Purchases, Identifiers and Usage Data, because 1.6 runs install attribution once you answer Apple’s tracking prompt.

Which one should you pick?

Pick Habit Doom if outside accountability moves you and a camera does not put you off. Pick Sparky if autopilot opens are the problem and checks would make you quit. If neither fits, Apple’s free Screen Time does the lock alone. The table puts all three side by side, with each one’s main weakness included.

Habit Doom’s photo step is the real thing, carefully engineered and priced below ours. If a camera pointed at your open book is what gets the book opened, that is worth 145 MB of anyone’s phone.

Sparky is for the person whose problem is the volume of autopilot opens, and who quits habit apps out of shame. Sparky assumes your worst day still counts, banks the minutes you do not use, and never asks you to photograph a glass of water at 11 p.m. If you doubt the earning model itself, read the evidence for and against it first. No app in this category, ours included, has an outcome trial yet.

Sparky turns small habits into screen time you earn. Download it free on the App Store.