As a parent, I had a hard time persuading my ten-year-old to play full hour of piano everyday. I know it is not uncommon after talking with other parents. Sometimes, we have to go shopping and when we come back, my son will tell me he played an hour piano already while we are away. I can’t prove he did. Only when he messed up at the piano teacher’s place, I know he maybe only played for 10 minutes. So I decide to make an app for it. I leave my phone at home and I dial in using my wife’s cell phone when we are out. My app will pick-up the phone automatically, and silently so no one knows. If my son is playing piano, I can hear it through the phone. That’s how I came up with the Eavesdropper app idea.

But it is more than that. Eavesdropper can work in two different modes.

Auto Answer Mode

In this mode, the phone will ring as normal but it will pick-up the phone automatically for you according to the settings. You can choose to auto-answer all calls, just calls from contracts or favorites, or just a few phone numbers. You can also choose how many seconds to wait before answering the phone. For safe driving purpose, you should also choose to auto answer the phone only when a bluetooth device (such as headset or car hand-free system) is connected, or at least enable the speakerphone.

Eavesdrop Mode

You need two phones in this mode – the eavesdrop phone and the dial-in phone. The eavesdrop phone must be an Android phone that has this app installed. You leave it at a place you want to eavesdrop then call it from another phone (any type of phones, doesn\’t need to be an Android phone or a cell phone). The Android phone ringer is turned off in this mode so it will not ring when it receives a call. For security consideration, you should only enable eavesdrop mode when calling from a particular phone number that also belongs to you. The app will pick-up the phone based on the calling number and enter the eavesdropping mode automatically.

There are many ways to use this app in eavesdrop mode. For example, in eavesdrop mode, if you leave your phone a few feet from a baby, baby cries will be transmitted to the phone you are dialing from. Better than any other commercial baby monitoring systems which only transmits within certain distance, this app works from anywhere as long as there is a phone available. Here is another way to use it. You leave your eavesdrop phone at home in U.S., travel to Europe, call it from a hotel phone and listen to what is happening at your home. You might be surprised to hear all the noises, which could turn out to be your son is hosting a huge party when you guys are not home.


It will use your cell phone plan’s talk minutes when your phone is picked up automatically in either mode, so please consider taking advantage of free mobile to mobile calls and unlimited night and weekend minutes, especially using the app in the eavesdrop mode.

2. Even though we named the app a little evil, please respect local laws and use the app in legitimate and ethical ways, i.e. baby monitor, your own house audio monitor etc.


I would like to say thanks to Everysoft for their AutoAnswer open source project. It helps us a lot when writing this app.