See https://linuxphoneapps.org/categories/conference-companion/ - both Confy and Kongress are decent. And then there's a relict from N900 times: https://flathub.org/en/apps/at.priv.toastfreeware.ConfClerk
The color picker unfortunately is a wider issue, it's a standard component of IIRC libadwaita that's just used in Gajim.
OS updates are paywalled (subscription)
This, at least for the C2, has changed https://forum.sailfishos.org/t/long-term-sailfish-os-updates-free-of-charge-for-all-jolla-c2/23491 (likely because it's conflicting with EU law), and they've instead introduced a Voluntary Subscription.
Honestly, I rather pay for my OS than paying for it with my data / privacy or living in an ad-infested garbage fest.
Edit: and their mix up with some Russian business (not sure about the current status of it) also doesn’t help instill confidence.
That's history, see https://forum.sailfishos.org/t/sailfish-community-news-30th-november-jolla-reborn/17473.
This. Also, most AppImages are x86_64 only. If they don't explicitly say it's for aarch64/arm64 you are going to also need some fun architecture translation (box64, fex, ...) to make the thing run. At that point, it's in many cases easier to try building from source IMHO.
PS: Good luck on Wayland can also be added, given probonopd's (AppImage inventor) stance on Wayland. I'd advise to not waste time with AppImages on #MobileLinux.
+1 for Gapless. My library is not nearly as large, but it's still plenty quick (no noticeable delay) with my 1 digit gigabytes library and IMHO the best native feeling media player on Phosh/GNOME Mobile.
It also does the Album -> Artist -> Song thing (which made me notice that I still have not fixed every error in metadata I managed to add to a part of my Library by blindly applying musicbraiz suggestions via Tagger, but that's just a me thing).
It's pretty much "real". You can install every package in the repos via apt, and they should work. Caveats can apply with regards to stuff that needs extra adjustment for accelerated graphics or new kernel features.
It's not a font ... and it says LINMOB (for LINux on MOBile).
I drew it in GIMP ages ago (15 years maybe?); and did not have the time to come up with a new logo since. (I am not super happy with it myself - but it's not a priority, there's way more important stuff I don't have time for).
That said: Contributions welcome! (at https://framagit.org/linmob/linmob.frama.io)
This is great, even if at least one app in that collection is only available for x86_64, which makes it hard to actually run on a phone ;-) They also updated the Device Support section of metainfo guidelines: https://docs.flathub.org/docs/for-app-authors/metainfo-guidelines/#device-support . Looks like some apps on the KDE side still need proper metainfo to show up: https://invent.kde.org/teams/flathub/issues/-/issues/34
Modern Android? More like Modern GNOME - it's called adwaitapod and adwaita is the name of GNOME's style. :-)
That's an option, https://linuxphoneapps.org/apps/dev.geopjr.archives/ can also read zim files, but I've found it to be a bit clunky - still, I recommend giving it a try.