You may want to take a look at FSNotes
>FSNotes is an open source project and is provided for free, but you can support development by buying application in App Store or Mac App Store for symbolic price.
I'm a big fan of FSNotes, which is currently my favorite flavor of Notational Velocity-inspired apps, and ticks all of your boxes nicely. I have it mapped to CMD-CTRL-ALT-N, so it's always at the ready when I need to add or (rapidly) find old notes. As a bonus, the notes are stored as plain text files, so you can easily move them to other apps if/when your needs change.
I use auto rename by title feature of FSNotes App for macOS and iOS to use the first line of the notes to be the name of the file. Even if I change the heading of the note, file is auto renamed, so other apps which do not support UUID can easily locate the files and open the wikilinks.
There’s an interesting alternative to Bear which is open sourced https://fsnot.es. I’m not affiliated with them and I’m using Bear myself, but seeing this effort is really cool.
P.S. I also am a developer and big fan of open source.
I use FSNotes on macOS. It's a minimalist Markdown-optimized editor in the lineage of the search-and-create modality originated by Notational Velocity (and forks of it like nvAlt). I can find the bit of text I need amongst thousands of notes with only a few keystrokes. It's also the only notes app I've found who's entire window can be made narrow so it fits nicely at the side of the screen (with list of notes at top just below the search box).
I use iA Writer on iOS.
These two apps sync easily via iCloud, but I've had issues with iCloud not having files always available and up-to-date; I would go to open a file while offline, e.g., while on a flight, and it wouldn't be found or be an old version. So instead I manage all notes in a git repository managed with Working Copy, and have automations that regularly commit, push, and pull file changes.
I previously used nvALT but have recently switched to FSNotes, also on github.
I like it's updated interface, some light rendering of the markdown, and that it's frequently updated. There are still a couple of highlighting or rendering bugs when notes mix code and standard content but it's certainly worth a shot based on what you're looking for.
Hi, guys!
I am FSNotes author https://fsnot.es – subscription free, open source app.
File system notes manager is modern "notational velocity" (nvALT) on steroids for macOS and iOS.
Application respects open formats: plain/text, markdown, rtf, and stores data in file system. Sync with macOS works through iCloudDrive, but Dropbox support planned too.