BUMP!
Croppy Extension now works for Tapas AND Webtoon!! That means you can go publish your comic, click the bookmark and these websites will work how you always dreamed they should, you upload your image and it just does all the reizing and slicing for you! May be alittle slower on tapas because Croppy will convert to PNG on tapas rather than JPG, but that means higher quality for tapas croppy!
May require you close your browser and all tabs completely, and reopen it before it works the first time- especially if you were using the webtoon version before. You'll know it's including tapas when the pop up mentions tapas ^_^