A quick list maybe
| Lubuntu 18.04 category | Lubuntu 18.04 | Lubuntu 20.04 |
|---|---|---|
| Accessories | Archive Manager | Ark |
| Accessories | Disks | KDE Partition Manager |
| Accessories | File Manager (PCManFM) | PCMANFM-Qt |
| Accessories | Galculator | KCalc |
| Accessories | Image Viewer (gpicview) | LXImage |
| Accessories | Leafpad | Featherpad |
| Accessories | Xpad | |
| Accessories | nobleNote | |
| Graphics | Document Viewer | qpdfview |
| Graphics | Simple Scan | Skanlite |
| Graphics | mtPaint graphic editor | LibreOffice Draw |
| Internet | Firefox Web Browser | Firefox Web Browser |
| Internet | Pidgin Internet Messenger | |
| Internet | Quassel IRC | |
| Internet | Sylpheed | Trojita |
| Internet | Transmission | Qtransmission |
| Office | Abiword | LibreOffice Writer |
| Office | Gnumeric | LibreOffice Calc |
| Office | LibreOffice Impress | |
| Office | LibreOffice Math | |
| Sound & Video | Audacious | VLC |
| Sound & Video | GNOME MPV | VLC |
| Sound & Video | PulseAudio Volume Control | PulseAudio Volume Control |
| Sound & Video | XFburn | K3b |
| Sound & Video | gucview | |
| System Tools | Gdebi | Muon Package Manager |
| System Tools | Gparted | KDE Partition Manager |
| System Tools | htop | htop |
| System Tools | LX-Terminal | Qterminal |
| System Tools | Software | Discover |
| System Tools | Software Updater | Discover or “Apply Full Upgrade” |
| System Tools | Startup Disk Creator | Startup Disk Creator |
| System Tools | Synaptic Package Manager | Muon Package Manager |
| System Tools | System Profiler and Benchmark | |
| System Tools | Task Manager | qps |
| System Tools | Time and Date | Date and Time (LXQt settings) |
| System Tools | Users and Groups | Users and Groups (LXQt settings) |
This was done via a Lubuntu 18.04.4 ‘live’ system (20200203) and compared with a Lubuntu 20.04 default install. It was done quickly and I may have made errors, or omitted some.
(The Pidgin & Quassel don’t quite line up intentionally, that’s me however Quassel can be used to replace Pidgin for many use cases)
Original at https://docs.google.com/spreadsheets/d/1ehbS4wB6WeODkK998-y0fOJwDDeaWLqYFvgeLas7b_o/edit?usp=sharing