Hi everyone, it's been a while!
As we're now working hard on updating Hotglue and expanding its features, I want to share what to expect.
This list (in no particular order within each group) combines what you -- the users -- have asked for over the years with things we've always wanted to add.
Some are already done; others are on the way. Share your ideas! 
https://github.com/k0a1a/hotglue2/tree/ng
You can try "nightly" version in action here: https://hotglue.me/ng
Already done
- Rebuilt, faster, modern editor (works on current browsers and devices)
- Sharper images on high-resolution / retina screens
- Modern, more secure login & password reset
- Online status / shows an error if saving didn't succeed
- Assign custom CSS class/id to any object via the UI
In progress
- Mobile viewing - mark which elements matter on phones and how they stack (page modes: absolute vs. screen-relative)
- Object rotate (90° steps, then free rotation), flip/mirror, shadows, rounded corners
- Copy pages / copy objects between pages
- Redesigned menu icons
- New uploader & better upload handling
- Custom favicons (add if you're doing it)
- Server-side video transcoding (1 min videos)
- Upload & manage your own fonts
- Undo (built on the existing revision system)
On the horizon (exploring)
- Object layering & nesting; select an object underneath another; contextual "list all objects on this page"
- Define object properties by hand (size, color, font size); color swatch from your page's dominant colors
- Edit an element's markup/code directly
- Better embeds (SoundCloud, YouTube, TikTok, Bandcampetc.) - easier to move & select
- Making PDF viewable
- Link improvements: target selector (internal → same tab, external → new), relative internal links, make part of a text a link
- A dedicated "settings" page (moving non-visual controls off the canvas)
- Menus that work while hovering objects (via a keyboard modifier)
- Move threshold on click (prevents accidental drags)
- See all object outlines on hover (find hidden objects)
- Offline buffering - hold changes and commit when back online
- Collaborative editing (owner shares access tokens ??)
- A per-page "store" objects can read/write
- "Glue" browser add-on - grab any element from any site onto your page
