If you want a robust and reliable network scanner for your mobile device, you should give Fing a chance. Read more about Fing  

Fing is a free and super-fast network scanner which can help discover which devices are connected to any Wi-fi network, map those devices, detect intruders that are scanning for vulnerabilities, reveal any problems with security, and test the performance of the network.
The application itself comes with some embedded tools such as Wi-Fi scanner, port scanner, DNS lookup, ping, and service monitoring, just to name a few.
With Fing, you can scan for opened TCP ports, analyze NetBIOS, UPNP and Bonjour names, properties and device types, get full details about devices including IP address, MAC address, Device Name, Vendor, Device Manufacturer, check for Internet connectivity, and much more.