I'm not going to post a zip archive of scripts (I wouldn't download a random script and run it myself), so instead, here are the contents of the scripts I use with Xcode. You can save these as shell scripts, and trigger them from Xcode (under Preferences → Behaviours). You might need to run chmod +x /path/to/script to get it to run, it depends how you're running it.
building.sh
#!/bin/zsh
/Applications/BuildWatcher.app/Contents/MacOS/BuildWatcher set building
error.sh
#!/bin/zsh
/Applications/BuildWatcher.app/Contents/MacOS/BuildWatcher set error
failed.sh
#!/bin/zsh
/Applications/BuildWatcher.app/Contents/MacOS/BuildWatcher set failed
success.sh
#!/bin/zsh
/Applications/BuildWatcher.app/Contents/MacOS/BuildWatcher set success
unset.sh
#!/bin/zsh
/Applications/BuildWatcher.app/Contents/MacOS/BuildWatcher set unset