If you're already using photoshop for your designs, I would argue that specking (http://www.wuwacorp.com/specking/) is more toward what you are looking for. It allows you to select your assets and provides detailed specs like font specs, attributes for size, position and distance between to items. Even allows you to adjust based on the screen density.
Also worth mentioning is PNG Express (http://www.pngexpress.com/) that does that plus some more. It's primary function is exporting assets for all types of use but it also has a specking feature for detailing the assets.
We use both of these here depending on the artist's preference but they take the guesswork (and man hours) out of figuring this stuff out and organizing it to hand off.
If you just want to annotate things, I would recommend Notable http://www.notableapp.com/. This isn't a photoshop plugin but allows you to annotate things and for them to provide feedback and questions as well.
If you're already using photoshop for your designs, I would argue that specking (http://www.wuwacorp.com/specking/) is more toward what you are looking for. It allows you to select your assets and provides detailed specs like font specs, attributes for size, position and distance between to items. Even allows you to adjust based on the screen density.
Also worth mentioning is PNG Express (http://www.pngexpress.com/) that does that plus some more. It's primary function is exporting assets for all types of use but it also has a specking feature for detailing the assets.
We use both of these here depending on the artist's preference but they take the guesswork (and man hours) out of figuring this stuff out and organizing it to hand off.
If you just want to annotate things, I would recommend Notable http://www.notableapp.com/. This isn't a photoshop plugin but allows you to annotate things and for them to provide feedback and questions as well.