I have designed my whole Android application in Sketch. I need to export the specs and assets for Developer. I was browsing through couple of Sketch Plugins to help ease it down for me but they exporting the groups instead of individual layers. I know it is possible to directly export from Sketch but is there any easier way to do the whole thing process of generating assets and specs.
I recommend you to try Markly, it's completely free to use. Markly is a free design collaboration app for macOS to help designers export, share & organize assets, enable developers to inspect design spec with 1 click. https://marklyapp.com/
For the Icons itself I extract them and create separate artboards for each and use the following settings: https://twitter.com/martinthiemann/status/535082123976531968
For specification, maybe have a look at https://zeplin.io
I use the plugin "measure" to make the "pixel perfect" and export each asset with the slicer or the "Make exportable" tool down to the right on Sketch.
The quickest method I've found is through one particular Android friendly export plugin. You don't need to manage slices and it'll do multiple platforms for you.
The method Martin described is another I've tried but you'll want to copy your slices and rename/resize them so that you don't have to enter all of the dpi sizes in every time.
As for spec'ing, I use and have contributed to sketch-measure because it's awesome and I love it. But it can be time consuming and without additional plugin support ends up putting a bunch of spec data in the way. Zeplin (as others have also suggested) is the tool I've always dreamt of for this process and it's definitely worth checking out.
I've been using Zeplin.io for specs lately and am so excited about it. It allows devs to view the sketch files and easily get all of the information they might need (colors, sizes, spacing, etc. etc.) without me having to spec each piece individually. It's still in Beta so not fully feature complete but the team is responsive and it's free! Definitely worth checking out if you find yourself spec'ing a lot of screens.