Here is another water sensor that detects flooding and leaks to save you major trouble at home. The Wasserstein WiFi Water Sensor is battery powered. It has a compact size, so you can fit it into the smallest gaps. No separate hub is required to use this.
The Wasserstein Water Sensor is compatible with iOS and Android devices. The bottom of it has 3 gold-plated probes to detect and alert you of possible flooding.