Why a physical key beats one more app

Every software-only blocker eventually meets the same adversary: a determined user with administrator rights over their own device. That user knows the uninstall path, the settings toggle, the safe-mode trick. They are not a hacker. They are you, at 11pm.

Friction that cannot be optimised away

Software friction erodes. The first time a confirmation dialog appears you read it. By the tenth time your thumb finds the button before your eyes find the words. Any delay you can wait out, you learn to wait out.

Physical distance does not erode. The key is either within Bluetooth range or it is not. There is no habituation curve on walking to the next room, and no clever sequence of taps that shortens it.

The key is only a key

Worth being precise about what the hardware does and does not do. The key does not block anything. It has no idea which apps you have chosen, it stores no usage data, and it never talks to the internet. All blocking is done by your phone, using the operating system's own official APIs — the Screen Time stack on iOS, an accessibility service on Android.

Those two stacks are not equally strong. Android allows a blocker to hold on more tightly than iOS does, and rather than quietly averaging the two into a promise we cannot keep on both, we document the difference and let you decide what it means for your phone.

The key's entire job is to answer one question convincingly: am I actually here? It answers with cryptography rather than a broadcast, which is what stops the answer from being recorded and replayed.

• No account required for core blocking.
• No usage data leaves your device.
• The key holds one secret and answers one question.

One purchase, not a subscription

There is a second asymmetry here, and it is commercial. Software-only blockers are nearly all subscriptions, which puts the company on the wrong side of the incentive. A blocker you cancel is a blocker that stopped being worth paying for, so the product quietly gets optimised for renewal rather than for the day you no longer need it.

Spark is built the other way round. The app is free and stays free — locking, choosing what to block, all of it. The key is the thing you buy, once, priced in rupees and quoted before GST, with a proper GST invoice and free shipping across India. There is no recurring charge, nothing to cancel, and no version of this product that gets worse when you stop paying, because you already stopped.