If you're already using Sketch and need to work out the handover process, Zeplin is my tool of choice over Invision's Inspect. I just feel it's a simpler, easier interface.

I also find it's easier for developers to navigate as Zeplin has fewer artboards uploaded. Invision is a prototyping environment for us so it has a lot of wireframes and concepts which don't make it to Zeplin.

Though if you're after an offline solution, Marketch hasn't been updated in ages. I much prefer Sketch Measure in a pinch if I'm having terrible connection.