The delayed mirror app, explained

Q: Is ReplayR a delayed mirror app?

Yes, since August 2026. ReplayR Pro has a Delayed preview mode: the camera screen plays back what the lens saw 5, 10, 15 or 30 seconds ago while the rolling buffer keeps recording underneath. That is the delayed mirror model, and ReplayR is unusual in running it on Android, where the established delay apps are iOS only. It also keeps the other model: a tap, Wear OS watch press or open-palm gesture saves the last N seconds as an MP4 with slow motion. So one phone covers both the unattended “watch every rep” station and the “keep the attempts worth comparing” workflow. Two limits worth knowing: the mirror is video only with no sound, and a save always captures the live footage, not the delayed picture on screen.

By Erwan Alliaume

TL;DR. A delayed mirror shows the camera feed on a fixed lag, usually 10 to 15 seconds for short skills, so you finish the rep, look up, and watch yourself from the outside, no hands, no operator. There are two models for seeing your own training: the continuous delayed feed (every rep replays, nothing kept) and the rolling buffer with triggered saves (only flagged reps kept, as clips with slow motion). Since August 2026 ReplayR Pro runs both on one Android phone: Delayed preview at 5, 10, 15 or 30 seconds, on top of the buffer it already had. This page explains both models honestly, including where each one still loses.

How does a delayed mirror work?

The app holds the last N seconds of camera frames in memory and displays them N seconds late. Set a 15 second delay, do a turn, walk two steps to the screen: your turn is just starting to play. There is no record button, no saving, no interaction at all; frames older than the delay window are discarded. The screen is effectively a mirror into the immediate past, which fixes the fundamental problem of real mirrors: you cannot watch yourself mid-jump, mid-turn, or mid-lift, because you are busy doing it.

The right delay is movement duration plus walking time. Short skills sit around 10 to 15 seconds; a full dance phrase needs the phrase length plus about 5 seconds. Our replay delay reference lists per-sport numbers, and the principle from motor learning research holds here too: feedback lands best within about 20 seconds, while the felt attempt is fresh.

Continuous delay vs replay-on-demand

Continuous delayed feed

Every rep replays automatically on the lag; nothing is kept, nobody operates anything. Best for unattended stations with high rep counts: a barre, a tumbling strip, a PE class rotating through. BaM Video Delay is the established app in this model, with delays from 1 second to 6 minutes, though it is iOS only and has had no active development in years. On Android, ReplayR Pro’s Delayed preview covers the same model at 5, 10, 15 or 30 seconds. The cost of the pure version: full camera and screen duty the whole session, and at the end you have nothing to compare, share, or slow down.

Rolling buffer with triggered saves

The camera records continuously into temporary memory; a tap, Wear OS watch press, or open-palm gesture keeps the last N seconds as an MP4. Best when attempts differ in value: the breakthrough double turn, the lift that moved differently. You end the session with a folder of the reps that mattered, each ready for 0.5× or 0.25× review and peer-to-peer sharing. This is the model ReplayR started with, and it still runs while the delayed mirror is on screen, so the two are not a choice you have to make.

Honest rule: the delayed feed answers “what did that look like?” in the moment and leaves nothing behind; the buffer answers “how does this compare to last month?” and needs someone to trigger it. Kept clips compound, in slow motion, side by side in your gallery, so a session with no saves ends with nothing. On Android you no longer have to pick: ReplayR runs the mirror on the screen and the buffer underneath it, and a save still captures the live footage rather than the delayed picture.

Continuous-delay reference app: BaM Video Delay, still on sale on the App Store, iOS only, no meaningful updates in years. Last verified 2026-08-01.

A delayed mirror on Android: ReplayR's Delayed preview

The delay-mirror category grew up on iOS and mostly stopped there. Since August 2026 ReplayR Pro ships the model on Android: switch Delayed preview on and the camera screen shows the footage 5, 10, 15 or 30 seconds old, continuously, with a badge and an accent border so a lagging picture is never mistaken for a frozen camera. Recording is untouched underneath.

One tap to change the lag. A pill on the camera screen cycles the four presets; the same value lives in Settings. Changing it re-anchors the picture without stopping the session.
Saving stays live. A tap, watch press or open-palm gesture writes the last N seconds of real time, not the delayed picture on screen. The app says so the first time you turn the mode on.
Video only. The mirror has no sound. Saved clips still keep their audio, and can be muted afterwards on Pro.
Android, seamless recording mode. The delayed player reads finalized ~3-second segments, which is what makes a 5-second lag reachable; the classic recording mode writes blocks too long for that. A 0s setting removes the feature and its pill, and switching it off does not need Pro.

The practical effect is that the two models stop being a device decision. One phone on a tripod replays every rep for whoever is training, and the same phone still holds a buffer a coach or a palm gesture can turn into a clip.

Setup recipes

Dance studio

Tripod at the mirror's corner, full body in frame, 15 second delay for turns and jumps or phrase length plus 5 seconds for combinations. Dancers glance at the screen as they pass. In ReplayR, set Delayed preview to 15s and leave the phone alone; the open-palm gesture (Pro) still saves a phrase without breaking position. See ReplayR for dancers and musicians.

Gymnastics station

End of the tumbling strip or beside the vault landing mat, 15 to 20 second delay: run-up, skill, landing, walk to the screen. ReplayR’s longest preset is 30s, which covers run-up, skill, landing and the walk back. For coached sessions where the coach picks the attempts worth keeping, the watch trigger runs at the same time as the mirror.

Weight room

Side-on at hip height. A 30 second delay lets you rack the bar and turn around to watch the whole set. Lifting also suits the buffer well, since sets have clear ends and a wrist trigger is natural; running both is the point. See ReplayR for weightlifting form checks.

FAQ

What is a delayed mirror app?

An app that shows the camera feed on a fixed lag, typically 5 to 30 seconds, so you finish a movement, look up at the screen, and watch yourself doing it moments ago. Like a mirror, but showing the immediate past instead of the present, which lets you see a jump, a turn, or a lift from the outside without touching anything.

Is ReplayR a delayed mirror app?

Yes, since August 2026. ReplayR Pro has a Delayed preview mode: the camera screen plays back what the lens saw 5, 10, 15 or 30 seconds ago while the rolling buffer keeps recording underneath. That is the delayed mirror model, and ReplayR is unusual in running it on Android, where the established delay apps are iOS only. It also keeps the other model: a tap, Wear OS watch press or open-palm gesture saves the last N seconds as an MP4 with slow motion. So one phone covers both the unattended “watch every rep” station and the “keep the attempts worth comparing” workflow. Two limits worth knowing: the mirror is video only with no sound, and a save always captures the live footage, not the delayed picture on screen.

What delay should I set for a training mirror?

Movement duration plus walking time to the screen. Short skills work well around 10 to 15 seconds: a jump or turn takes 2 to 4 seconds, and the lag leaves time to finish and look up. Longer phrases need the full phrase length plus about 5 seconds. If you reach the screen too early you wait; too late and the rep has already played.

Can I build a delayed mirror station with a spare phone?

Yes, this is the standard setup: an old phone or tablet on a tripod beside the studio mirror or platform, running a continuous-delay app, plugged into a power bank for sessions past 90 minutes. Athletes glance at it after each rep, nobody operates anything. On Android the spare phone can run ReplayR itself with Delayed preview on, which means the same device also holds a buffer someone can trigger a save from. Many coaches still keep a second phone with ReplayR for the attempts worth comparing over time.