The idea: you gift someone an hour of undivided time. To redeem it, you launch this ap, put your phone in airplane mode and into a white paper envelope and seal it. The screen stays on, it glows through the paper like a small lantern, showing an hourglass in which luminous sand flows upward (time doesn't run out, it collects!).*
There is deliberately no app blocking. You switch to airplane mode yourself, and the sealed envelope does the rest. I think any programmatic lock can be circumvented anyway. This whole thing runs on cooperation, which is exactly what a gift assumes. Pulling the phone out early means visibly breaking a promise to a person, not to an app.
The "product" is not technical, but I try to establish a "ceremony" or "ritual", where the user conciously decides to not use their phone and to spend time with a loved one.
Technically it's one self-contained HTML file: canvas animation, Screen Wake Lock, works offline once loaded, no accounts, no analytics (none at all, the app has no backend, hosted on github).
My goal would be, if this gets any interest, to maybe sell some envelopes with printed instructions, stickers to seal and a link to the app. But anyone can use it for free as well. The code is MIT licenced and you can find it here: https://github.com/grothkopp/presentoftime
*Standard paper weights might be a little to thick, so "transparent" envelopes might be necessary for the full effect.