I have a few errands to run, but I will make an inventory example tonight, and I'll make that my first video. The basic process is you make an inventory panel, then you create an inventory object as a child. You set the size of each square on the inventory, then you set image panel objects as children on the inventory object. They will automatically snap to a grid when parented to an inventory object. They will also never overlap each other. They fire a condition if you try to drop an object on another object.
There's an expression on the inventory object that will let you see if the inventory has any space, and another expression that tells you where the first available space is.
Each object in the inventory is an image panel. Image panels are kind of like sprites but instead of Construct handling them, GWEN handles them. They are GUI objects that can be docked and so forth. They have a load from external image action, and more importantly, a set UV action. Set UV means you can load a giant image with all your inventory object art on it, like this, and then make image panels with that image. Set UV will let you select which object you want the image to represent. This saves a lot of memory in the long run. Like I said, I created each widget thinking about long term implications.
Another example of that is that each and every widget has a "set data" action and a "get data" expression. "Data" can be anything you want, a string, integer, float, whatever. The cool thing is that you can use set data on all of the image panels to set statistics for the object that it represents. (It's name, damage, etc.) Set and Get Data are found in the common widget options, since they affect all widgets.
I will have the example cap and Youtube video for all this functionality ready tonight.