Hello.
I took this as an learning weekend project and i build up this, i know that main request was to 'not use source' counter but unfortunately i am not that good at programming yet and you have to link text document ("counterText.txt") to your resources to see the count. Anyways i made you this small customable counter which use HotKeys to add or remove your count.
It is pretty small in file size, and i hope it is also easy to use.
I made the default HotKyes:
ALT+SHIFT+P to add
ALT+SHIFT+O to remove
ALT+SHIFT+I to reset.
But they can be remaped anytime under "settings".
You can also change your tray icon by changing ICO (I am using 32x32 format) file in folder.
Build & tested under win8.1 64bit. Please post your Feedback. Thanks.