Wi-Fi is not technically an application, but it is an invaluable source of data that should be examined, so we'll briefly discuss it here. Wi-Fi connection data is found in /data/misc/wifi/wpa_supplicant.conf. The wpa_supplicant.conf file contains a list of access points that the user has chosen to connect to automatically (this is set by default when a new access point is connected to). Access points that the user has forgotten through the device settings will not be shown. If the access point requires a password, that is also stored in the file in plaintext. In the following example, the NETGEAR60 access point required a password (ancientshoe601), while hhonors did not:
The presence of an SSID in this file does NOT mean that this device connected to that access point. These settings are saved to a user's Google account, and added to the device when that account is set up. An examiner can only conclude that the user connected to these access points from some Android device, not necessarily the device being examined.