First-day-of-school photos: the doorstep series

The same doorstep, the same pose, a taller kid: the first-day series is the best longitudinal photography most families ever produce.

The idea

Every year's shot in one rotation turns the series into what it wanted to be — a floating growth chart, running all year.

In practice

The senior-year shot next to the kindergarten shot, arriving unprompted in February, is the whole reason this app exists.

Setting it up

Ten minutes, once: install Bubbles In Time ($2.99, one-time), pull the relevant photos from your gallery into the rotation, set a frequency that feels right, and let the floating layer do the rest. Everything stays on your device — no account, no uploads, no ads between the memories — and the pause switch is always one tap away.