TFS 2015+ on premise (Build 2.0) notifier/watcher - Currently in alpha state
Sample command line:
TFSBuildNotifier.exe "http://host/Collection/project/_apis/build/builds?definitions=865&$top=1&api-version=2.0&statusFilter=completed"
(You can have multiple Urls on the command line, separated by spaces)
You can download a .zip file with the latest build of the master branch from AppVeyor