Slowglass Long Exposure Camera

Light trails, silky water and star trails, built live from the camera stream, on phones whose stock camera has no long exposure mode.
Rest the phone on a tripod or a wall, tap once, and watch the exposure grow for a second, half an hour, or until you tap stop.
One price, and no internet permission at all.

FIVE WAYS TO SLOW THE GLASS
Light trails: headlights draw lines across the frame.
Silky water: waterfalls turn to mist.
Motion blur: moving traffic smears while street lights stay sharp.
Star trails: bright stars and planets drawn into arcs over a long session.
Lightning: each strike saved from the frames just before the flash, plus a storm photo when you stop.

EXPOSURES WITHOUT A TIME LIMIT
Pick 1 second, 30 minutes or unlimited, and stop whenever you like, from the screen, a volume key or the notification. Long sessions keep running with the screen dimmed or while you use another app. A tripod delay keeps your tap out of the first frames.

HONEST OUTPUT
Photos are saved at the size your camera streams to the app, often 1920 x 1080. This is not full sensor resolution, and Slowglass tells you the exact size on first launch. It can also save the sharpest single frame beside each stack, and writes the session length and frame count into the photo's details.

A CAMERA CHECK BEFORE YOU RELY ON IT
On first launch a short camera check measures what your phone can do: the stream size, the frame rate while stacking, whether a low frame rate for stars is accepted, and whether infinity focus works. Share the report if you need help.
Tested on a Samsung Galaxy S22+ running Android 14, where stacks save at 3840 x 2160.

YOUR SESSIONS, YOUR FILES
Photos are ordinary files in Pictures/Slowglass. Export the session log as JSON or CSV, or send it through the share sheet, and import the JSON on a new phone.

WHAT IT DOES NOT DO
No manual ISO or white balance, no RAW, no video and no hand-held alignment. Use a tripod or something steady.

One-time purchase. No ads, no subscription, no account. Works fully offline.