For lightweight & quick conceptual work, even final deliveries most of the time, nothing beats a browser based available-everywhere tool. No files to sync, same tool to both view & edit the files.

I used Industry heavyweight Photoshop for 15+ years, Sketch for 4 and dropped everything for Figma[1] after playing with it for 2 days. Now my UX comps, UI sketches all available EVERYWHERE. All inspirations, rough concepts all stacked away in any browser I have access to. I move to different machines a lot (Macs/Windows). Used to carry around a USB stick (synced to Dropbox from my home computer).

Now it is nirvana - No syncing, No dropboxing or figuring out where my prototypes, v1, 'final-final-v1-1-edit-final' files, & source files are. Not only the files are available, but the viewer to view those files are right there.

[1] www.Figma.com - Browser based UX Mockup/Prototype tool.