
After using it on three devices for several months, I'm delighted with it. All store locally and sync to my Nextcloud. Powerful, stable, open and interoperable - what more could you ask for?
I have been using Joplin for several years, on mobile devices, Windows and Linux. It is great. On mobile devices, it may be that the sync has to be triggered more often so that all notes are synchronized. On mobile devices, the sync may need to be triggered frequently to synchronize all notes. This is especially true if you have a lot of notes.
This is one of my favorite open source projects! Also, if you're looking to get better at markdown, this is the app to do it. The free sync is fantastic - because it integrates with dropbox, and because most of what you're syncing is just text, you can use this for quite a while before reaching the dropbox free-tier limit. I can keep a journal at work and have it sync to my phone, personal workstation, and other devices. It's really quick and most importantly - a decent community and still actively developed!
Take your notes anywhere: on your phone, laptop, tablet, etc and have them synced to each other. Plenty of plugins to make your work even easier. Save websites as html, markdown or images. Create todos from your notes.