Meet the Wi-Fi Siren from D-Link: a smart device that works with mydlink-enabled connected home devices to alert you when things are happening around your home. It can be paired with a motion sensor to get alerts when movement is detected near doorways, windows, and other areas. You can also pair it with your WiFi water sensor to detect leaks.
The device is easy to set up and offers 6 different alarm sounds. Its volume is adjustable via a mobile app. The WiFi Siren emits a noise ( up to 100 dB) to alert you or keep intruders away. Sets you back under $65 at this time.