I’ve written a tool which allows you to load a spritesheet image such as the kind used in games (where all contained sprites are laid out in a grid) and click on individual sprites to see a magnified version of them, including the coordinates, column, row and index of the selected sprite. I developed a need for this sort of utility while working with Phaser, where you reference specific sprites or frames within a spritesheet by index rather than by coordinate. Seeing as how this is a common mechanism when it comes to game development I figured there are a plethora of other languages & libraries where such a tool could be useful, so I’ve made it available on github.
Get started with the hosted version now at: http://nefd.github.io/spritesheet-indexer/
You can find the github repo here: http://github.com/nefD/spritesheet-indexer