A graphical 'advanced' package manager for Qt / KDE. Something to replace Muon which is/was the KDE equivalent of Synaptic but no longer available in Kubuntu. Discover shows you apps (both snap and apt), Muon showed packages with all sort of relevant technical information (source, dependencies, 'reverse dependencies', installed files). I guess everything Synaptic/Muon does is also available through the various apt subcommands but there is value in a decent GUI to bundle those individual commands and their output.

Calibre https://calibre-ebook.com/

Pursuing feature parity with Calibre would be a long journey, but we have to start somewhere

WinSCP is a Windows tool I use at work to send files between machines and I wish there was linux version. Programs like Dolphin are similar but I always manage to find something I can do in WinSCP that I can't do in the linux alternatives

Edit: commenters just pointed out a bunch of potential solutions I wasn't even aware of, so I'm probably just dumb please carry on

A nice editor for both Markdown and reStructuredText with minimal dependencies, which allows to change seamlessly editing between rendered text and source text. Like one has a tab for source text, and one for rendered text, and can change and edit both tabs.

Gollum wiki has something similar but it could be better. Maybe even having two panes side-by-side, left source, right rendering, and one can edit both and / or flip them.

Also, I think one could find a ton of small useful improvements in Zim Wiki. I use it all the time to gather and structure information on poorly documented stuff, which is very often needed when working with legacy software, and it is great and extremely useful but not perfect.

Some QT or Cosmic takes on Pika Backup. The maybe unrealistic dream would be some new non gtk photo dam that ignores editing all together and hands off files as needed to an editor like vkdt. Kinda like Adobe Bridge.

Pebble app. There's Rockwork, but outside of Ubuntu Touch it will only produce empty notifications. There's Rockpool, that's only for SailfishOS. There's Amazfish, but so far it can only pair and then... nothing.

• Bulk unarchiver or a frontend for ffmpeg (using existing tools, both get very messy when special characters or multiple directories are involved)
  • Existing ffmpeg GUIs have had fixed lists of formats and options, making new or obscure ones inaccessible. There also needs to be an option to export the command based on GUI selections so the user can learn if they choose, or fix the command if something isn't right.
• Adding the little details of Windows File Manager (i.e. Format dialog, search by attribute like MP3 bitrate) to some existing Linux file manager
• Mounting of network drives in Linux graphical file managers: many of them handle it through gvfs, which for some reason insists on mountpoints with long directory paths and special characters, breaking compatibility with various utilities
• Extending Linux Mint's libadapta to further restore theming in libadwaita apps. This I am personally looking forward to contribute to as more programs move to libadwaita and disrupt the look I've painstakingly set up for my desktop.

I wish Divvy/WinDivvy worked on Linux. There are similar alternatives, but none that duplicate the functionality.

I kinda want an lcars interface for my phone, but I'm too lazy to configure it