The app works with android version > 2.3 (Gingerbread). The app has been officially tested with Nexus 4. Please contact me at google groups to report success/failure stories so that I can update supported devices here.

Tested: Nexus 4, Nexus 5, Samsung Note-3, Galaxy S4, Moto Droid Razer maxx

The app has the below configuration:
1. Capture Options:
  a. Capture Image: Captures image as jpeg from front camera.
  b. Capture Location: Captures location using GPS/Network in the best time/accuracy possible.
  c. Show scare screen: Display a warning message to the intruder who is trying to unlock your device after alert has been sent.
  d. Capture on number of wrong unlock attempts: Alert when wrong unlock attempt equals this.
2. Storage Options:
  a. Save in Gallery: When checked the pic/location data is saved in a folder under DCIM and added to gallery else data is stored internally.
  b. Delete after Alert: When checked the pic/location data is deleted from the device after the alert has been issued.
3. Connectivity Options:
  a. Use Wifi Always: Uses wifi to send alert. (takes time if wifi off)
  b. Use Data Always: Preferred. Uses network data to send alert. (fastest)
  c. Wifi followed by data: Tries wifi first, if not not available then tries data. (slowest as it tries both)
4. Email Alert Options:
  a. Enable Email Alert: When checked sends email. The data sent to the server is RSA/AES encrypted. The data is not stored in any database or in sent folders of the alert emailer. If you lose the alert email data then there is no way to recover it back.
  b. To: The email address alert to send to.
  c. Subject: Default subject is shown as hint. You can change if you wish. Helps for filtering/forwarding purposes.
  d. Device Name: Default is Android. It is used in the email subject by replace #DeviceName and possibly in email body. 
5. Dropbox Options:
  a. Enable Dropbox Upload: When checked you will have to approve Unlock Alert app to create its app folder where it will upload the alert data. Note that the app does not have permission to access anything else in users dropbox account.
6. On: When clicked you must allow app to monitor unlock attempts.
7. Test: Runs a test with the current configuration. Please note to run this and see if the app works with your device.

Permissions Requested
android.permission.CAMERA: To capture image from front camera to alert.
android.permission.WRITE_EXTERNAL_STORAGE: To save the image/location data in device.
android.permission.ACCESS_FINE_LOCATION: To collect location data using GPS for including in the alert.
android.permission.INTERNET: To send alerts using email and dropbox.
android.permission.ACCESS_NETWORK_STATE: To check connectivity to internet.
android.permission.CHANGE_NETWORK_STATE: To enable data.
android.permission.ACCESS_WIFI_STATE: To check connectivity to internet through wifi.
android.permission.CHANGE_WIFI_STATE: To switch on wifi if off.

If the app crashes when you run test, try disabling camera capture option and run test again. Please report the results at Google Group.

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I am hosting 2-3 redundancy server for this free app to alert using email. I plan to buy a domain to use for description and emails. If you think this app is useful please consider donating the domain for a period of atleast 5 years.