There are somewhere in the region of 1600 unicode symbols and you can render Unicode in your Power Apps. Basically it’s a number that represents a symbol or a picture, such as an Emoticon, or a picture of some clouds etc. Here’s a little vid on how to use this page and how to use unicode in your apps.
For Power Apps the structure you need to use a HTML text label and the structure for the HTMLText property. This is my version of “Hello World”
The report below shows a large number of unicode characters that are available for use in your apps.