Enable easy preview of any screen(s) and linking to those screens on Zeplin from within Jira issues.

Illustrator is still a contending tool, is it in the plans?

It's pretty new but promising:

https://affinity.serif.com

Adobe XD support!

Provide plugin for Adobe XD, just like sketch plugin,
so that it will be very easy to develop the product.

Tagging is nice but it's not the solution we need to organise our files. We're having trouble organising multiple pages, page flows and component flows across multiple breakpoints on large scale projects. If we could create folder structures for pages it would make life a whole lot easier.

Convert SVG assest to VectorDrawables for since Android cant load SVG out of the box. You can load a VectorDrawable out of the box.

see https://developer.android.com/training/material/drawables.html#VectorDrawables
and for converting svg to vectordrawable see http://inloop.github.io/svg2android/

Yesterday i wanted to work in an offline situation, but i had to connect my macbook via iPhone to the internet to see the screens i'm working on

SAML support would help us give a more secure access to devs in a large company

Similar to the Slack integration suggested, a method with which HipChat can get notified when changes are made. In our HipChat, commits and builds are put into the chat whenever developers make changes. Would be cool to have my design changes being integrated too.

Can import Photoshop files and generates specs automatically

It would be absolutely amazing if you can "export" a document (pdf?) with the details. Like a document for developers.

Instead of px measurements generated in the font style CSS, support rem and em measurements.

Ideally with an option to set the html base font-size. (Bootstrap 3 for example sets html's font-size to 10px, which allows 1.6rem to equal 16px, unless someone edits their browser's options to increase font size.)

Currently, Zeplin doesn't allow a developer to change the name of the file when they are downloading the assets. It is set to auto-override an old asset.

This behavior generally works well, but there should be an option for someone to change the name of the file they are saving.

Being able to tag screens is a really nice feature, but when I do any kind of responsive design/multi-screen feature, the amount of screens can get pretty lengthy. I'd like to be able to group them together. Many times, one dev is working on one feature and they have a rough time finding a screen even when tagged. It's also rough when re-ordering screens to find the right one it goes next to.

Use OS X native notifications to alert everyone when a new comment or screen has been added to a project.

I wish to be able to export SVG assets for my iOS project type. It's nice to have that I have that capability with web projects, but it becomes more limited for iOS/Android.

Add ability to duplicate a project, which means if you want to create a new version of a project you have to start from scratch with content, and members (yes, you have to individually invite every member to the new project, see next point).