I find that 1280x720 seems to work really well for making multiple supported screensizes without code. However, I am developing a responsive app maker extension (Using Gamemaker Studio), which gets the correct scale and units that google recommends using for app design. This is what I use to create a foundation for a scale.
** Takes the Density-independent Pixels (dp) value and converts it to screen pixels
** Input: integer : Density-independent Pixels
** Output: integer : Screen Pixels
** This will allow you to make sure everything is drawn the same across different Android Devices
var dp = argument0;
return dp * (display_get_dpi_x() / 160);
160 is the default value, there are 5 different values that could be.
Then I just call to it whenever I need a value converted, like instead of
which scales it rather nicely (With some tweaks here and there). You can also try using the following functions: