Pool - Collaborative lists

Little teaser of a collaborative list app I've been working on with Travis Bogosian. We'll be in the Apple App Store by the end of the month.

Anyone have tips on exporting artboards from Sketch for Dribbble? Ideally I'd like the whole image to be the thumbnail without looking pixelated.

I exported this 800 x 600 artboard at 2x, but had to crop the thumbnail. I also tried doing a 400 x 300 artboard at 1x, but it looked way too pixelated.

Looking forward to hearing your suggestions. Thanks!