Does not let you adust the dimensions once you take your finger off of the key, like you can do when cropping a photo, for instance. If the cursor starts slightly off of where you want it, you have to start all over again.

Perfeito. Facilita demais o meu trabalho.

Doesn't help much, because you can't move the selected area or correct/change its borders after selection. That means, if you did not hit the area to be measured pixel-exactly at the first go, you have to repeat the measurement until it fits as desired sometime.

Size in Pixels makes no sense with me. I need size in cm/inches, something eas for you to do if you use the screen size, resolution and pixels. Why should I do it, when a simple add-on to the add-on can easily do it. Until change implemete I'll discard "Measure it". Even with "paint.net" I can easier get/adjust size for optical purposees.

Good. it definitely does what it proposes. But it should have a percentage option. Percentage relative to the window in width and height.

Mas que buena. Muy útil sobre todo para desarrolladores y diseñadores que quieren sacar medidas en la pantalla.

De uso muy fácil. ¡¡¡100% recomendada!!!

Unfortunately, it doesn't work on all websites (I'm not talking about *.mozilla.org).

Installed in Mozilla and Chrome, now works correctly on a site outside Mozilla, which I havent tried before. Sorry

Great addon. Does what you'd expect. My only question is, when will it support Firefox mobile view? That would be the only thing I'd say it is missing.

Works as expected. Useful. I did not notice any performance degradation. Thanks.