Apps like Wi-Fi Analyser only show Wi-Fi traffic unfortunately as it's not a full spectrum analyser. I've been using it for years :-) It's good for seeing neighbours networks and picking a different channel (assuming the neighbours don't have channel hopping enabled). What it doesn't show is interference in from non-Wi-Fi devices in the 2.4Ghz spectrum, such s DECT phones (mine is 1.9Ghz), Bluetooth (I had fun 'killing' my wife's mouse during testing), Microwave ovens, etc. I've never really seen a noteable performance difference before, probably because my ADSL 2+ link maxed out at 10Mb down, and less than 1Mb up.
... View more