WhatPulse opens a so-called "keyhook" when it's booted, which listens to incoming Windows messages about the keyboard, the keyhook sends these messages to the program itself, and the program first determines if the key pressed is a proper key (Every standard keyboards' keys are counted) and then simply does PreviousKeyCount + 1.
Pulsing: When you "pulse", you're actually sending your keycounts in the program to the server along with other information about your Account, so the server can decide where to put the keycount. If the pulse goes according to plan, the server sends back an "OK", and the client's keycount is reset to 0
This is a list of deviantART members that use WhatPulse.
If you use WhatPulse, and want to be added to the list, send a PM to WhatPulse (https://www.deviantart.com/whatpulse) and we'll add you to the list! :)