I posted a piece of art and someone correctly assumed it was made on Krita. They said they can usually tell.
And I saw some art recently and thought it was done on Krita, and it was. But I could not tell you why I think this.
Is this a thing?
If so, what are the signs?
Some of the default brushes are pretty telling and when people use them you can sometimes identify the application by its iconic brushes or textures (if they have it). Photoshop for example has a default grass brush that is absolutely ugly and overused by beginner artists a lot and when you see this you just know it probably was Photoshop. Sometimes you can also tell by the brush engines, especially the smudge brushes. Since most Applications have their own implementations you can sometimes tell by the way they smudge or blend.