As you may know, P.S. Notes is a free and open-source software note taking application that permits the users to easily write notes, save them on the cloud and sync them with other devices, via Dropbox.
It also has a filter bar, for searching for notes.
The latest version available is P.S. Notes 0.11.8, which has been recently released.
Up to date P.S. Notes packages are available via some third party PPA, so installing the software on Ubuntu 16.04 Xenial Xerus, Ubuntu 15.10 Wily Werewolf, Ubuntu 14.04 Trusty Tahr, Linux Mint 17.x, Elementary OS 0.3 Freya and other Ubuntu derivative systems is easy.
All you need to do is add the PPA to your system, update the local repository index and install the psnotes package:
$ sudo add-apt-repository ppa:thejambi/thejambi
$ sudo apt-get update
$ sudo apt-get install psnotes
Optional, to remove psnotes, do:
$ sudo apt-get remove psnotes