You cannot recover a moment the camera never saw, but you can keep the camera always seeing. A buffer camera app holds the most recent seconds of video in memory while it is open. When you tap record, it writes that buffered past to a file, so the clip starts before your tap. On iPhone, Video Buffer Action Camera keeps a rolling buffer of 2 to 100 seconds.
Why the built-in Camera app cannot do this
The iOS Camera app starts writing video the instant you press the button and not a frame earlier. Live Photos reach a moment back, but only 1.5 seconds and only around a photo. So the usual options have been bad ones: record everything and scrub through an hour of footage later, or accept that the moment is gone. The moment is usually gone, because interesting things do not announce themselves.
How a rolling buffer works
A buffer camera flips the order of events. From the second you open it, the camera continuously captures video into a short rolling window in memory. New frames push out the oldest ones, so the app always holds exactly the last N seconds, and nothing is saved to your storage yet. Then two things can happen:
- Nothing interesting occurs. The frames age out and disappear. Hours of pointing the camera cost you zero storage.
- Something happens. You tap record. The app saves the buffered seconds from before your tap and keeps recording until you stop it.
Dash cams and security cameras have worked this way for years, and GoPro ships it as HindSight. The same mechanic on a phone means the camera you actually have with you can record the past.
Save the last 30 seconds, or the last 100
How long should the buffer be? Match it to how long a moment takes to unfold plus your reaction time:
| Situation | Buffer that works |
|---|---|
| Kids playing, funny pet moments | 5 to 10 seconds |
| A single play in a ball game | 15 to 30 seconds |
| A full attack sequence, a race lap, a storm front | 60 to 100 seconds |
Reaction time matters less than you would think. Even if you tap five seconds late, a 30-second buffer still hands you the whole play.
Set it up step by step
- Open Video Buffer Action Camera and tap the clock button next to the record button.
- Pick your buffer length. The number on the central record button, for example "30s", always shows what you will get.
- Point the phone at the action, or put it on a tripod. The screen can stay on for hours; the app keeps the phone awake.
- When the moment happens, tap the record button, tap anywhere on the screen, or press a volume button. The clip that gets saved starts 30 seconds in the past.
- Tap stop when the action is over, or turn on Save Buffer Only in Settings and the app stops and saves by itself, one tap per finished clip.
Three buffers at once
Moments come in different sizes. With Multiple Buffer Times enabled in Settings, the app shows three record buttons, each with its own buffer length, for example 5, 20, and 100 seconds. A quick laugh gets the short button, a full play gets the long one, and you decide at tap time, after you have seen the moment.
Do this in Video Buffer Action Camera
The whole workflow above is the app: a rolling buffer of 2 to 100 seconds (up to 10 minutes for audio-only), the Buffer duration picker, Multiple Buffer Times with three record buttons, Save Buffer Only for one-tap clips, and triggers by screen tap, volume button, or Apple Watch. Record in 4K or at 240 fps slow motion, and save to Photos, Files, or iCloud Drive.
