Let's look at these plug-ins:
This plug-in can reduce the UI designer output to the developer's workflow, it will output an Html file, automatic tagging the size of the layer above, color, size.
Developers use annotations file can be more convenient for development.
Before I use the Affinity is exported as PSD, then use www.biaonimeia.com to output.But I will meet a problem here, textLayer into the Image layer after layer exported as PSD.
So now, for the moment, Affinity workflow, unable to solve the problem of automatic tagging.
Don't know Affinity Team will add this function in this respect.If you want to meet this requirement is not too difficult, personal understanding of the ideas are as follows:
1. The traversal of the layer properties: layer size, position, font color, font type, font size.
2. The reference source sample at https://github.com/tudou527/marketch
3. Generate Html files as attachments.
Attachment on one of my use the Sketch automatic output sample: GUIOut.zip
I like Affinity Designer, so I put forward its own ideas, hope don't mind.