wavemon!

Let's face it-- there's SOOO much Wi-Fi everywhere these days, the built-in Wi-Fi tools and free utilities that used to help us understand the Wi-Fi environment just can't keep up anymore. Those tools don't help you see how many access points are in the same network, nor how many SSIDs a specific radio is broadcasting.

Munin is a networked resource monitoring tool that can help analyze resource trends and "what just happened to kill our performance?" problems. It is designed to be very plug and play. A default installation provides a lot of graphs with almost no work.

NetStumbler is a tool for Windows that allows you to detect Wireless Local Area Networks (WLANs) using 802.11b, 802.11a and 802.11g. It has many uses:Verify that your network is set up the way you intended, find locations with poor coverage in your WLAN, detect other networks that might be causing interference with your network, detect unauthorized "rogue" access points in your workplace, help aim directional antennas for long-haul WLAN links & use it recreationally for WarDriving.Does not work well with Win7. This software has not been updated in years and harkens back to Win Vista days. »

Kismet is an 802.11 layer2 wireless network detector, sniffer, and intrusion detection system. Kismet will work with any wireless card which supports raw monitoring (rfmon) mode, and (with appropriate hardware) can sniff 802.11b, 802.11a, 802.11g, and 802.11n traffic. Kismet also supports plugins which allow sniffing other media such as DECT.

With Homedale you can search for Wi-Fi / WLAN Access Points and monitor their signal strength. Use the detected access points with Google Geolocation and Mozilla Location Service to locate yourself.

Cacti is a complete frontend to RRDTool, it stores all of the necessary information to create graphs and populate them with data in a MySQL database. The frontend is completely PHP driven. Along with being able to maintain graphs, data sources, and Round Robin archives in a database, cacti handles the data gathering. There is also SNMP support for those used to creating traffic graphs with MRTG.

vnStat is a console-based network traffic monitor for Linux and BSD that keeps a log of network traffic for the selected interface(s). It uses the network interface statistics provided by the kernel as information source. This means that vnStat won't actually be sniffing any traffic and also ensures light use of system resources. However, in Linux at least a 2.2 series kernel is required.

How strong is your WiFi signal?

Ethstatus is a console-based monitoring utility for displaying statistical data of the ethernet interface on a quantity basis. It is similar to iptraf but is meant to run as a permanent console task to monitor the network load.

Virtual Wifi Hotspot is a free software router for Windows based system running Windows 7, Windows 8, Windows Server 2008 R2 and Windows Server 2012.Using Virtual Wifi Hotspot, you can share any internet connection Via Wireless Internet my come from Wifi or LAN or Cable Modem or Dial-up or Cellular, etc.. The internet can be used by any Wifi device such as Laptop or desktop or Smart Phone or iPod Touch or iPhone or Ipad or Android Phone or Zune or Netbook or PS3 or wireless printer, etc.. These Wirelessls connecting devices can connect to Virtual Wifi Hotspot just like any other WiFi Router.Virtual WiFi hotspot is protected by Password and the underlaying security is WPA2 »

darkstat is a packet sniffer which runs as a background process, captures network traffic, calculates statistics and serves them to a web browser.

TrafShow continuously display the information regarding packet traffic on the configured network interface that match the boolean expression. It periodically sorts and updates this information. This funny program may be useful for locating suspicious network traffic on the net or to evaluate current utilization of the network interface.