HueNote is a text editor that can edit in parallel multiple notes. You can set the editor any number in the range of window size. Of course, you can also use in the editor only to one as a simple note-taking app. The notes written a lot is managed by the library. You can also be registered frequently used notes to the reference list.
Note: The demo version is currently at 1.2.2; the version available for purchase is 1.3.