For mobile apps, I slice and properly name all assets into folders named for each screen. Most of the time I sit next to the developer and give them colors, fonts, positioning. Otherwise I make a blueprinted spec with everything called out (pixel spacing, colors, fonts, etc). In the past we created an indesign file with a list of all the colors and fonts called out, then a comp of each screen with all the pixel spacing. This became wildly out of date too fast and the time it took to maintain it, made it not worth it.
For mobile apps, I slice and properly name all assets into folders named for each screen. Most of the time I sit next to the developer and give them colors, fonts, positioning. Otherwise I make a blueprinted spec with everything called out (pixel spacing, colors, fonts, etc). In the past we created an indesign file with a list of all the colors and fonts called out, then a comp of each screen with all the pixel spacing. This became wildly out of date too fast and the time it took to maintain it, made it not worth it.