Intrude: Motion Detection Cam

Intrude is a motion detector, trail camera and home security camera that runs on your phone. Point it at a bird feeder, a nest box, a doorway, a driveway, a pet bed, or anywhere else you want to keep an eye on. Arm it and it records clips locally when something moves.

Intrude works offline. Your video never leaves the phone. There is no sign up, no email and no password, because there is no server holding anything of yours to log in to. The only things that need a connection are the one-time Pro purchase and, if you leave it on, anonymous crash reporting.

WAYS TO USE IT

Bird camera. Set the phone behind a window facing a feeder or a nest box and catch the visit you always miss.

Trail camera. Watch a hedgehog run, a gap in the hedge or a garden path in daylight, at dusk, or in a lit area.

Pet camera. Leave it running indoors and find out what the dog actually does when you go out.

Home security camera. Cover a doorway, a driveway, a shed or a hallway and review what happened while you were out.

FREE MOTION DETECTION

The free app compares camera frames on the device several times a second, so motion detection works with no internet and no wifi. It records clips that begin two seconds before movement, so you see someone arrive instead of the aftermath.

Before recording, Intrude filters out cast shadows, headlight beams and knocks to the phone. That is the difference between a motion detector you can leave running all night and one you switch off after an hour of false alarms. Sensitivity adapts as the light drops, and Intrude can watch the light level and turn the phone's torch on by itself when it gets dark, then leave it on until the session ends.

Choose a siren the moment motion is detected, or keep it silent. Detection can keep running with the screen off, behind one quiet notification with a Stop control.

Free recording goes up to 720p. Review clips by session, step through them frame by frame, then save or share one clip at a time. Free clips carry a small burned-in Intrude mark. There are no ads in either tier.

Intrude never deletes old clips to make room. When free space runs low, recording stops instead.

INTRUDE PRO

Pro is a one-time purchase, not a subscription. It unlocks:

Subject filters that record only people, animals or vehicles, using an on-device labeler. Watch for people and let the fox cross the driveway at 3am.
Detection zones, so you can draw over the parts of the view that matter. The doorway gets watched, the curtain by the open window does not.
1080p and 4K recording.
Clips with no burned-in mark.
Save or share many clips at once, or export the whole clip library to one file in Downloads.
Slow and fast playback, and the option to save a still frame to your photos.

GOOD TO KNOW

Intrude does not send motion alerts or push notifications. It records when it sees movement, it can sound a siren, and you review the clips afterwards.

There is no live streaming and no remote viewing. This is a local camera, not a service you watch from a second phone.

There is no infrared night vision. Intrude can detect low light and switch the phone's torch on by itself, which is enough for a doorway or a feeder close to the lens, but it will not see across a dark garden the way a night vision camera would.

Not every phone is built for weather, so check your phone's water resistance before leaving it out in the rain. Shooting through a window or using a sheltered spot avoids the question entirely.

For long sessions, keep the phone on a charger or a power bank.