So I do this using Photoshop! Open that up with the image:

Then go to Layer Style, then click Pattern Overlay:

Then after that you can choose which pattern you want to use:

Then go to the Blend Mode (has it ‘Normal’ by default) and click Overlay!

This feels a bit too much, so I edit the amount of the effect by increasing and decreasing it with Scale:

You can make your own overlays to apply to Photoshop too! There’s a tutorial on that HERE:
(Though the pattern doesn’t have to be so small if you want, it can be full page sized, like the one I’m using)

Hope that helps!