An ios icon is 1024x1024. In GIMP, choose Image->Image Properties and it will give the pixels/mm. The sample icon I downloaded was 5.669 x 5.669 pixels/mm.
25.4 mm = 1 inch
5.669 x 5.669 pixels/mm -> 144 dpi
Toggle with option-command-enter
An ios icon is 1024x1024. In GIMP, choose Image->Image Properties and it will give the pixels/mm. The sample icon I downloaded was 5.669 x 5.669 pixels/mm.
25.4 mm = 1 inch
5.669 x 5.669 pixels/mm -> 144 dpi
Toggle with option-command-enter