Offline sound analysis
Recognises potentially relevant sound patterns locally and associates saved recordings with detected activity.
ANDROID ACTIVITY MONITORING · BY PRAESCIUS
Know what happened while you were away.
Understand sound and phone-handling activity in a space you're authorised to monitor — without relying on a remote monitoring server.
PraeGuard analyses events on your Android phone, creates a readable timeline, and lets you review the evidence. Optional Pro features add photographic capture, Gmail alerts and detailed exports.
Preparing for Google Play · Download link will appear after release
EXAMPLE INCIDENTPhone moved and screen activated
The phone registered movement while its screen became active.
Illustrative interface summary, not a live monitoring result.
What PraeGuard does
Evidence you can follow. Not just sensor readings.
A simple workflow connects audio classification, device activity and available photographs, with plain-English summaries and the underlying files ready for review.
Phone handling
Tracks movement, rotation and screen or connection events that Android makes available.
Optional photo evidence
Triggered camera capture helps add visual context, when enabled and permitted by the device.
Readable evidence timeline
See what happened in order, mark your own activity and set aside incidents you wish to disregard.
Optional Gmail alerts
Send selected summaries and available evidence through the Google account you authorise.
Reviewable exports
Export selected incidents with files and checksums, or retain a broader evidence archive.
The evidence experience
Review the moments that matter.
PraeGuard groups nearby observations into incidents rather than making you sift through raw acceleration values and audio model scores.
17:29
Phone handling detected
Movement and rotation observed.
17:32
Screen became active
A separate observation—not automatically an unlock.
17:35
Review your activity
Mark your return as yours, ignore it or keep it included.
Example events for illustration. PraeGuard does not infer a person's identity or prove entry from these signals.
ACTUAL PRAEGUARD APP SCREEN
Screenshot from a development build; final screens may differ.
Screenshot from a development build; final screens may differ.Simple workflow
Place. Arm. Review.
Choose your monitoring options
Use a phone you control, in an authorised location. Select whether photo capture or remote alerts are needed.
Arm PraeGuard
Leave the phone in position during the exit countdown and environmental baseline period.
Review and export
Disarm, check the evidence timeline, and decide which incidents belong in your report.
Important limitation
Sound classification and motion sensing are indicators, not proof of unauthorised entry. Camera access can be limited while Android is locked, and background alerts may be delayed. Recording indicators remain visible.
Free to start
Start with core monitoring. Unlock more with Pro.
Planned Google Play pricing. Pro is intended to be a single in-app purchase rather than a subscription; the published store price takes precedence.
PraeGuard Free
£0Useful local monitoring without a recurring charge.
- Local sound and movement monitoring
- Incident timeline and audio playback
- Mark as mine / Ignore events
- Basic local evidence review
PraeGuard Pro
£9.99Richer evidence and remote notifications.
- Everything in Free
- Optional handling-triggered photographs
- Optional Gmail incident alerts
- Complete or reviewed ZIP evidence exports
- Advanced email alert controls
PraeGuard is not yet available for public purchase from this page. The Play Store listing will provide final pricing, compatibility and purchase terms. Praecheck licensing is entirely separate.
The details
Questions worth asking.
Does PraeGuard upload recordings to Praescius?
No Praescius evidence-upload service is included in the current architecture. Monitoring and sound classification run on the device. Optional Gmail alerts transfer chosen files through your authorised Google account to your chosen recipient.
Will it work without internet?
Local detection and evidence review work offline. Remote Gmail alerts and purchase verification require a connection. Queued alerts depend on Android and Google account availability.
Can I exclude my own return to the room?
Yes. Mark an incident as yours or ignored. That removes it from the reviewed export while leaving the original local evidence available for reclassification.
Is this a hidden surveillance app?
No. PraeGuard is intended for transparent, user-initiated monitoring of spaces where recording is authorised. Android privacy indicators and monitoring notifications are not concealed.