I'm working on an app where the Main Activity has an Overflow Menu, that has two option/items in it About and Help. What I want is a way that if I clicked on say About, a card would come up on the screen over the Main Activity (not hiding it completely, being translucent) to show some text. I have looked it up and I have seen people talking about 'Dialogue Boxes'. I don't want that because it doesn't look "Material Designed", so if there is any other way I could achieve it or if there's some way I could make the Dialogue Box look like a "Card floating above the Main Activity".
I can assure you that dialogs are part of the material design, see https://www.google.com/design/spec/components/dialogs.html#dialogs-specs
But if you want to show more than very little information, I'd suggest you create an About activity.