Several feature suggestions have been mentioned multiple times in the forum and on GitHub, so I’ve compiled them for easy access. I plan to update this list, so let me know if you have something to add 
INFRASTRUCTURE //
- Clips with instancing (When you create a clip, changes to it affect all other copies of it. As seen in Flash.)
- Make clips show up in asset library
- Mouse X/Y displayed on screen
- Hold shift to maintain aspect ratio when resizing
ART TOOLS //
- Brush tool pressure sensitivity (available for testing in master branch)
- Choose which frames are onion skinned
- Clip effects (filters - color, blur, shadow, glow, etc.)
- Snap to grid & snap alignment
SCRIPTING //
- Touch event support (in progress)
EXPORTS & MEDIA //
- Downloadable desktop version (in progress)
- Community site for uploading animations (sometime in the future; see Wick Project Sharing Website)
- Export as .PNG image / sequence
WEBSITE & FORUM //
- Upload .zip files