A steel ball rolls through a tray of sand and traces each digit. When the minute changes, a rake smooths the old one away and the ball writes the new.
Coming soon to Google PlayFor Android phones and tablets. Free, with no ads.
This is not a picture of sand. Each grain is there on the tray: pushed aside by the ball, banked up along the edge of a stroke, combed into furrows by the rake.
Once a minute you get a few seconds of something worth watching. The rest of the time it sits still, and rests your battery.
Change the sand, the tray, the shape of the digits and what writes them. Or lay the sand down as a picture and write the time across it.
Eleven flags, laid grain by grain. Tilt the phone and the picture gathers itself back together.
Write in coloured sand instead. A vacuum lifts the old digit before the new one is poured.
Four sands, three trays, three styles of digit, and a ball, a marble or a fine stylus to write with.
It is a tray of sand, so it does what sand does.
Then leave it alone, and the clock quietly puts the time back.
Set a few stones on the tray and switch the garden on. A small rake takes its time: rings round each stone, waves across the open sand, a line traced round the numbers.
Each pattern is drawn once and left in peace until something disturbs it.
The clock, the wallpaper, the screen saver and all the sand play are free.
Not now, not later. Nothing flashes at you from a clock.
Extra sands, pictures, digit styles, tools and the zen garden are unlocked with points. You start with some, and can buy more in the app.
Sign in with Google only if you want points, so that what you unlock follows you to your next phone.