While standing beside that oak tree you found, you save that location and call it oak tree.
Next time you park your truck, open the app and bring up that saved oak tree location.
A picture of the oak tree area will open and will be marked with a teardrop icon, "like Kevin's camp is marked in the picture below here", and your location where you are standing will have a blue circle.
You can see where the oak tree is and what direction you need to walk.
As you walk, that blue circle will be moving keeping your body position marked.
If I open the app in my house on one end and walk 40 feet to the other end of the house, that blue circle moves to the other end of the house where I am standing.
I would say it is accurate to within 15 feet at least.
There is also a compass on the top right side of the apps picture, pointing north, which I circled for ya.