Resolution

The purpose of the Resolution app is to

* collect some statistics to better understand what users of their phones can and can't see in relation to their screen resolution/density.

* give you a better understanding of what you can see. So that you can make more informed purchasing decisions.

It can't test resolutions higher than your the resolution of your display. But given how most modern displays work*, if you can make out the detail at 1px, you can likely get benefit from a higher resolution display.

*Most modern displays make use of the individual RGB components to simulate a higher resolution than you would naturally get with the physical number of complete RGB groups. This sacrifices a little quality for the given logical resolution, but makes much better use of the RGB components that are actually there.

You can read more here: https://www.randomksandom.com/resolution/