Guard2 runs silently on an Android device and sends you an email alert the moment that device goes offline or stops being used — no accounts, no subscriptions, no complexity.
Anyone who wants quiet, reliable assurance that the people they care about are active and reachable — without intrusive surveillance.
If your parent hasn't unlocked their phone in 12 hours, Guard2 alerts you immediately. No wearable device needed — just their regular smartphone.
College students, boarding school kids, or children traveling alone. Know their device is active without texting them every few hours.
Different time zones make it hard to stay in sync. Guard2 bridges the gap — you'll know if something is wrong before you even wake up.
Hiking, road trips, remote locations. If the device goes dark, your emergency contact gets an alert so they know to check in.
Monitor multiple people from a single email inbox. Each device sends alerts independently, so you always know who needs attention.
Some people simply don't respond to messages. Guard2 tells you their device is alive and active — that alone is peace of mind.
Install once, configure in under a minute, then forget about it. Guard2 runs quietly in the background — you only hear from it when something is wrong.
Download the APK and install it on the device you want to monitor (a family member's phone, a parent's tablet, etc.).
Give the device a recognizable name (e.g. "Dad's Phone") and enter the email addresses that should receive alerts. No account creation required.
A lightweight foreground service keeps running in the background, sending a heartbeat every 30 minutes. Battery impact is minimal.
If no heartbeat is received for 2+ hours, or the screen hasn't been unlocked in 12+ hours, all designated recipients get an alert email instantly.
As soon as the device comes back online or the screen is unlocked, a recovery notification is sent — so you're never left wondering.
Guard2 is intentionally minimal — built to do one thing extremely well.
Automatic heartbeat every 30 minutes, survives screen lock, app kill, and device restart.
Detects whether someone physically unlocked the device in the last 30-minute window.
Alert up to 3 email addresses simultaneously. All recipients receive every alert type independently.
When the situation resolves — device comes back online, screen is unlocked — everyone is notified right away.
If no heartbeat is received for 48 hours, the device record is automatically removed and a final notification is sent.
No location data. No contacts. No media. Only a random device ID, a nickname, and your chosen email addresses.
No server to manage. No account to create. The backend is fully managed — just install and start.
Monitor multiple devices using the same recipient email. Each device has its own nickname for easy identification.
| Type | Trigger | Subject Line |
|---|---|---|
| ⚠️ Heartbeat Alert | No heartbeat for >2 hours | [Guard2 Alert] Device "…" needs attention |
| ⚠️ Unlock Alert | Screen not unlocked for >12 hours | [Guard2 Alert] Device "…" needs attention |
| 💚 Heartbeat Recovery | Heartbeat resumes after alert | [Guard2 Recovery] Device "…" heartbeat restored |
| 🔓 Unlock Recovery | Screen unlocked after alert | [Guard2 Recovery] Device "…" screen unlocked |
| ✓ Monitoring Started | User taps START | [Guard2] Device "…" monitoring started |
| ■ Monitoring Stopped | User taps STOP | [Guard2] Device "…" monitoring stopped |
| 🗑️ Auto-Removed | No heartbeat for >48 hours | [Guard2] Device "…" auto-removed |