I'm new to libgdx and I have a question:
How can I implement a ScreenViewport? I created a new class but I think that is not enough. I'm developing a game and therefore I need the viewport so that every device is gets supported.
I also developed a score but without a viewport the texture will be on different positions on the screen. However, I want it on a certain position! Hope someone can help me. Thanks!
World size of ScreenViewport is based on the size of the screen so for different screen size, you'll get different world size.
You should take a look of libgdx wiki, and choose appropriate viewport for your requirement.
I'll recommend you to use ExtendViewport because it keeps the world aspect ratio without black bars. Check this answer.