[beaucollins]

What exactly do you mean by offline mode? No syncing to "the cloud" at all?

[im_dario]

I undestand "offline mode" as to be able to edit a note without connection and sync later.

I use (and pay) Evernote because of this. You can edit and create notes while disconnected.

[beaucollins]

Simplenote does this.

These are exactly the features Simperium provides.