fruux is based on open standards. We’re supporting CardDAV for contact and CalDAV for calendar and tasks synchronization.
Unfortunately no widely supported open standard for “notes” yet. Once there is one, we’d be interested in implementing it.
Another possibility would be to take a look at the VJOURNAL standard (which is not widely supported either though).Constanze commented
The ability to take and sync notes would be tremendously helpful to me, since I'm trying to replace my paper Filofax with fruux and I kept lots of notes in there. Is there any way the VJOURNAL standard could be used for that? With support in the web app and mobile app? That would be awesome :).