This indicator simply identifies if the markets are in an up or down trend. You should always use it in combination with other indicators, just as Wavetrends.
This indicator is mostly known because of Market Cipher. The script that was published under the name Wolfpack Id is for some reason closed source, but as it turns out there is of course no secret sauce involved, the original indicator goes way back and the thing that was then called Wolfpack Indicator is simply a MACD Signal Line with 3,8 settings. I added a simple divergence hunter for some extra Informations that might help, brought it up to contemporary pinescript standards, added Alerts and made the whole script open source, as it should be and as the original script also once was. Have fun!