First and foremost, thanks so much for developing this extension. It’s a fantastic beginning, My interest here is to request feature enhancements to make it even better and more like the legacy extension it’s replacing.
Feature Request
#1 SHA1 & MD5 calculations
Fortunately there is this https://addons.mozilla.org/en-US/firefox/addon/calculate-md5-sha1-hash-che-1/ but the extra steps involved is quite time consuming so please please please bring this back. I put this #1 because it is essential integral part for any download manager.
However, it used to be incorporated into the download status bar of legacy browser. When hovering over a download when complete MD5 hash calculation was displayed. I’m very hopeful it can be incorporated again
#2 Persistent Status Bar
In the legacy extension the bar was persistent at the bottom of the open browser window and not tied to certain tabs. Please make it so if possible
#3 Dynamic resizing of concurrent downloads
I’ve had up to 25 downloads of diverse types (.exe .jpg etc.) all remaining in a single height one row linear fashion. This may be achievable with unticking the show text option in your extension dialog, but I haven’t tried it yet.
#4 Thumbnail view
I download images a lot, so I like to be able to hover over and view a thumbnail image for expedience please bring this back.
#5 Scan for virus dialog
Indispensable we really need this as it was in the legacy extension
#6 Double Click run or open file
Double click currently opens containing folder it should run exe or open image as it did with the legacy extension
#7 Play Sound when download complete
I loved that feature and wish you could bring it back maybe toggle on and off through settings dialog be nice if we could choose wav file but not necessary.

Great. I was really missing S3 Download Manager, and this is rapidly turning into a worthy replacement. Personally, though, I'd just like to see two changes: 1 - bar thinner; 2 - also showing the download speed while the download is still ongoing.

Thanks so much for making this.

Great add on, now I can see the status of my downloads

Good work. Needs improvement, but works well and I will be waiting for updates. Thanks!

Keine Anzeige während des Downloads. Es erscheinen nur die fertigen Downloads unten.

Das Design ist sehr einfach und die Anzeige der Downloads ist mir viel zu groß.

Great solution for this greatly missed feature. Thank you!

good jobs....
bravo

Very nice! I most missed the feature of Download Status Bar that let me open Explorer where I had saved a file, and this replacement does just that.

Good one!
Coming from Download Status Bar this is a nice starting point, finally I can see my downloads again and handle them. I thought the new WebExtentions APIs no longer allows access to downloads from a horizontal bar at the bottom of the window but it seems to be possible. I hope injecting html is allowed by Mozilla?
It would be nice if the bar would be a bit smaller and some colours added. Also an option to delete the download.
But this one is nice and the only alternative I found. Keep up your great work, 3 stars for now and because there is a space above up to 5 stars. It´s just 3 days old!
EDIT: One Star up for the fast feedback and update.

How can i change the color of the progress bar?

4 stars to ask the developer to continue his work ... before attribute him 5 *
Not yet equivalent to the "non-we" S3.Download , but on the way to !!

4 étoiles pour demander au développeur de continuer son travail... avant de lui attribuer 5 *
Pas encore équivalent au "non-we" S3.download, mais c'est en bonne voie !!

I was looking for a replacement for the "Download status bar" I used to have, but that doesnt work with Quantum. This is the best replacement I've found so far.
Its nothing fancy, no spiffy colours... just the way I like it. Simple and non-intrusive. Could use a few more features/options though.