I'm learning this all by playing this tonight:
Ground - This is your ground layer usally grass, sand, water, floor, rock.
Mask - This usually your fences, rocks, walkways, bridges.
Fringe - This is usually you plans and tree's (players hides under this).
Over - this is doing things like ledges and such (players hides under this).
Collision - This to place the red blocks to stop players from walking on it.
Object Group 4 - This is for things like portals, spawning, and TONS more
Now I'm not sure if Object layer needs to be called Object Group 4 I tried 3 and such but it went back to normal tileing.
I would like or love to have a crazy list of or most of them maybe with a example of Object Group 4 features.
This what I understand so far:
Name: Name of the object like warping outside but has no real purpose just self reference?
Type: warp, spawn I really like to learn the list of this.. Or pointed to the right spot in the source files

Then you add all the values and such like x and y and so forth.
Anyways I hope people could offer examples of many things you can do.
Edit:
1) How do you test your maps out?
2) I tried a new map making Object Group 4 and really anything and I could not make objects window. I edited a map from the git locally to test my skills and I guess that is why I was able to do it before. So I'm clueless how to make a object layer
