I read part of the paper. Note the graphs where the y axis is as short as possible to make the effect size look larger. The title is explicitly non-serious. They also represent that they can measure cognitive capacity and fluid intelligence reliably and meaningfully, instead of presenting the data more clearly in the form of... data, eg, raw text scores. It also lacks the sort of control group that has a non-smartphone distraction present, so there isn't conclusive evidence that its the smartphone itself. What if it was a chessboard or a sandwich?

They need to hold themselves to more serious standards, this makes science itself look bad