A free program for Android, by WIT Electronics Limited.
The Aiwit app is a free app that helps you monitor watch, hear, and speak to visitors at your house in high-definition video from anywhere. This is a perfect app if you are a busy person and need to do your work at home. You can easily check if there is someone at your front door without the need to stand and walk to your door.
It also has a simple device configuration that does not need to set up any information online. Moreover, you will also receive immediate notifications when visitors ring the doorbell or activate the PIR motion sensors.
