Network Discovery is described as 'Discover and Scan machines on your network from your Android phone' and is an app in the Network & Admin category. There are four alternatives to Network Discovery for a variety of platforms, including Windows, Android, Android Tablet, iPad and iPhone. The best alternative is Fing, which is free. Other great apps like Network Discovery are Port Authority (Free, Open Source), Wireless Network Watcher (Free) and ThingsPage (Paid).
A handy systems and security-focused tool, Port Authority is a very fast Android port scanner. Port Authority also allows you to quickly discover hosts on your network and will display useful network information about your device and other hosts.
ThingsPage Sensor software detects and authenticates endpoints without a dedicated hardware. No PC agents are required. Installing the Sensor at one Windows machine at each network makes it easy to have centralized management of multiple networks.