The app complies with the inclusion citeria
The app is not already listed in the repo or issue tracker.
The original app author has been notified (and supports the inclusion).
Several users have asked for this application to be included in F-Droid: https://github.com/laurent22/joplin/issues/15
The app is created using React Native but built using a gradle script so I think it is compatible with F-Droid.
Link to the source code:
Link to app in another app store:
Joplin - a note taking and to-do application with synchronization capabilities for Windows, macOS, Linux, Android and iOS. http://joplin.cozic.net
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor. The notes are in Markdown format.
Notes exported from Evernote via .enex files can be imported into Joplin, including the formatted content (which is converted to Markdown), resources (images, attachments, etc.) and complete metadata (geolocation, updated time, created time, etc.).
The notes can be synchronised with various targets including the file system (for example with a network directory) or with Microsoft OneDrive. When synchronising the notes, notebooks, tags and other metadata are saved to plain text files which can be easily inspected, backed up and moved around.