I would like to have my text appear and disappear in a certain area only. I was thinking of applying a layer mask to keep it visible in a certain square. I was wondering if that is possible?

Hi Kristof, I was pertaining to masking a text layer (a feature common in image manipulation tools). For example, if I mask a text layer using a rectangle, the text layer will only be visible inside the rectangle. Here is a quick video on masking layers but with Adobe After Effects. 

I believe that a loop or middle transition will not give me what I want. Basically I just want my text to start appearing in a certain area. Imagine a rectangle in the center of your screen. When the text goes inside the rectangle, the letters inside will be visible. Right now my solution is covering the outsides of the rectangle to hide the letters/text.

This is exactly what I want. In the video, they used "Shape Layer 1" to tell the text the area it should be visible/seen. This is what I pertained to as "masking the layer". Is this possibe in LayerSlider?