PortDroid is described as 'A network security and port scanning Android app' and is a network analyzer in the network & admin category. There are more than 25 alternatives to PortDroid for a variety of platforms, including Windows, Linux, Mac, Android and iPhone apps. The best PortDroid alternative is Nmap, which is both free and Open Source. Other great apps like PortDroid are Angry IP Scanner, Advanced IP Scanner, Zenmap and NetPeek.
NetworkArch is a network diagnostic app equipped with various tools, including pinging specific IP address or hostname, sending Wake on LAN magic packets, Whois and DNS Lookup.
