Hi Joplin users, nice to join you !
I've been using for years some good apps, for many respect, that act like organizer, note tacking and/or knowledge base. I can mention the great TheBrain (for pc mainly), Ultimate ToDo List, Notelynx, etc.
Then I've found an app that could sync between Linux and Android, and can be used for both notes and to-dos (what I've always been thinking is the right approach to PIM): Quire. It has also a clean and effective interface. Unfortunately is a cloud based app, syncing with their servers, while I'd prefer to sync with mine; not to say it's closed source.
Anyway, nothing was invented from scratch..
Now I've found Joplin and I like it. I don't know how old it is, but it appears to be growing like a very good piece of software, on correct basis.
So here's my idea for Joplin, a key feature request (In my modest opinion, of course 
) missing as now.
Virtual lists of items that are not notebooks, but the result of a query (like that's meant in relational databases). In other words a filter editor to crete filtered lists, to appear in the side pane, named with the filter's name . For example all the notes and to-dos, not completed, that are tagged 'bank' + 'car'.
Such an editor could essentially consist of evaluation lines - matching item's tags and flags to values - added to each other by boolean operators (eventually parenthesized).
That should be used to move items from one list to another, changing in a natural way a flag to 'done' or a priority attribute to 'urgent', or adding a tag 'to_buy', for instance.
In some contest those lists are called 'views' and can be sorted too (another cool feature).
I hope I've been clear enough in spite of my English.
What do you think ? Are anyone interested in this ?
Thanks for your nice job