A game / trail / security camera app or "camera trap", designed to run on your old phone. Capture photos, video, time-lapses, long exposures ( image stacking ) and stream live video using a second phone as the remote controller.
Features include; remotely controlled via browser, motion sensing / detection, sound & vibration detection, remote image viewing, real-time image streaming to browser, stream images/videos to Chromecast / Google-cast devices, extended time-lapses, long exposures and live stream video to a browser.

Images are saved to device's SDCARD/DCIM folder.
Photo quality is set to the highest available for the device.

I developed this app during the pandemic so that I could place my wife's old phone in a bird house and watch the chicks hatch. None of the other security-cam apps had the features I needed so I made Critter-cam. For more about the birdhouse project, see here; https://black-capped-chickadee.blogspot.com .
WIFI or a hotspot is required for intial setup. Not for use over mobile data connection. This is not a cloud app; all images stay on your device unless you transfer them yourself. They are easily downloaded via browser via the "Browse/Download" link on the apps web page. In a pinch, configuration can be done by long pressing the URL shown on the apps QR screen but it can be flaky as the app begins to capture images, it will interrupt your browser.
When setting up, be sure to take a test photo to see if your subject area is in the camera frame.
This app works best if the phone's display is unlocked.
Use the app on an older phone and delete all your user/google accounts prior to unlocking.
The app works best if the app is not Battery Optimized or device is continuously powered. Attaching a portable USB battery bank is also a great way to run the app for extended periods. Another method I use is a 19 volt laptop power supply to a long run (+30m) of network cable which terminates with a USB car charger that then powers the phone.
Keep in mind that unlike most trail cams, your phone does not take Infra-red night images and your phone is likely not water-proof. There are numerous see-through water tight phone cases but the cheap clear vinyl pouches work great.
This app does not use encryption and is not safe to use on public WIFI/data networks; doing so could compromise your device and disclose private photos.
Please use only on a secure private network or via a hotspot from another device.
All images are saved in SDCARD/DCIM/CritterCam folder in addition to being available through app's web interface. Quality of "Triggered" photos is limited by camera preview size.
Live Stream video at 1080p requires a very strong WiFi connection on both devices. If video appears janky then lower the quality to 480p. Live Streaming also requires a client browser that supports Media Source Extensions. You should expect about a 15 second delay in the video feed. It has been tested on Windows (Chrome,Edge,Firefox), Ipad (IOS 15) Safari, Android 12 (Chrome, Opera). Not all browsers correctly compensate for video/camera rotation meta data. For example, your live stream may play upside-down in Firefox but upside-right in Chrome. Live stream video cannot be Chromecast in this version.
For close-up subjects such as when mounting the phone inside a bird house, use the front/selfie camera as it is better for focusing near subjects.
When using the selfie camera the app can optionally display a "bait image" on screen such as a flower. Flash mode must be on. You must upload the bait image from your browser or second phone.