How do you mark up your design?

Hello everyone!

Is there any way to apply an engine / plugin against the photoshop layers to generate a spec automatically?

I saw there are some plugins out there, like Specctr, PNGExpress, Markly App, etc. Which one should I choose?

I think PNGExpress is not bad you can use it for your plugin work.

@Leon_Chu, If you have CC subscription you can upload the file to creative cloud and share it with developers so that they can get css and details themselves. Watch this video to understand how it works.
Also if the developer is using Brackets, they can do the same thing from there too.