How to keep an eye on someone through an Android phone without bothering the owner

Everyone cares about their significant others' security. We all know that feeling when your calls are not answered and your Whatsapp messages not marked as read. In a moment like that you would do a lot to have any idea what is happening there. Although cell phone carriers offer geolocation services to locate another user, knowing your girlfriend is somewhere in the middle of Main Street will barely help. So what can we do about it?


WARNING

All the information was obtained through author's personal research and is published for educational purposes. Neither the editorial staff nor the the author bear any responsibility for any damage caused by the intervention in the OS performance.

Setting goals

It's a good thing we live in happy times when just several lines of code can make your wish come true. Let's check what we can do with a regular Android phone.

Today we're going to write a short program that will work in background mode, gathering various data we need and then send it to a specified server.

We already created a similar nice application in one of our previous articles, but it was not able to run in the background. The reason lies in the app’s activity lifecycle. You are welcome to study this subject in detail. I'll give you just a brief description: once the system registers that the user stopped using an application, it goes to the queue for unloading from the memory to clear it for other tasks. So if we want the phone to collect the data throughout the day (and night) we should see to it.

We want our application to launch every now and then to take a photo with its front camera, record a short sound sample and send it all to a certain server. To make it flexible and adjustable let’s make it download a config file to check against once in a while.

Application scheme

Application scheme

Go!

Let's first create the XML configuration file. It will be downloaded once a day and parsed with XMLPullParser. In our case we should check for opening audio and photo tags. Clearly this class allow more opportunities, so creating flexible preferences will not be a problem. The preferences proper will be saved to Shared Preferences.

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