I currently developed two apps waiting for it to release in Jolla store
Public Finnish holidays and flag daya calendar
The second app is day countet app for important days like how many days till birthday or counts how old you are.
Are there some apps or ideas what i could try to develop next?
Enhance the public holidays app with support for more countries?
An app to track menstrual cycles, periods.
Personally (and I think also others) would like to have a public transport app available. Fahrplan used to have Matka.fi API, but it has been broken for some time. And it’s not available in the Jolla Store. So an app that would pass the Harbour validation and one could search departures using Matka.fi API would be awesome.
An app to navigate an offline Maanmitauslaitos map (they are opensource), great for hiking offline in Finland.
This is a great thread!
Everything Nextcloud for better integration. OS integration is already alright but I would love to more easily use Nextcloud natively on SFOS.
An idea, but probably very difficult:
Document writer. Something similar to Collabora Office or Google docs for editing documents on the fly. I use my phone more and more for this type of thing.
Native Collabora is being developed/ported.
Nextcloud News would have been something!
An app for the FreshRSS newsreader. That’s almost the only thing I still have to use Android (Capy Reader) for.
That is great news! 
There is some version of it (owncloud news?) but I never found it helpful. What kind of news can you get from that?
I would like there to be an option to see the news if swiping right or left like with the notifications (I know it is kind of copying android and possibly iOS, but it is helpful).
An app for translations. Possibly with different providers to choose from (Yandex, DeepL, Bing, Google…)
I use Nextcloud News for RSS and the current app we have, has limited functionality and requires Qt 6
There is Luna app but it seems years without update, don’t know how usable it is.
About app for translations… TAO Translator and Deepfish. I have unreleased app for Lingva Translate but API of instances aren’t much reliable.
Yes so none of those apps you mention are available in the Jolla store for 64bits phones (Xperia 10 II and onwards)
A native Qobuz client would be nice. There is an inofficial© linux client that may form the basis of a port:
TAO Translator. I’m using it right now on my 64bit phone.
Maep has that but it doesn’t work anymore.
Right right, but TAO cannot be found in the Jolla store for 64 bits phones. OP mentionned Jolla store apps.
Maep used to have that yes… Also another great Jolla Store 32bits hiking map app ("Haftrail’’ i think?) was letting you download MML map areas in advance…
Nextcloud recipes/cooking app (basically a frontend for the one nextcloud has already)
Amazing work! Can those days to be linked for native calendar app?
I’ve been accessing my Nextcloud News with Fuoten (successor of ocNews) from openrepos. It’s last updated 2023 but seems to still work fine.