Edit: Due to the fact that this article is old, the installation instructions may not work anymore. In order to successfully install the latest version of UberWriter, please access the uberwriter tag and open the latest article (the one on top).
UberWriter 15.05.01 has been recently released, bringing small fixes only.
UberWriter is an open-source writing application, with markdown support and features for exporting files to PDF, RTF, ODT and HTML, via pandoc. The software allows the users to write in either fullscreen or the focus mode, that highlights the sentence which is currently written.
The default skin provides a white background, some horizontal lines and a dark font, but the users can choose an inverted skin, having a dark background and white font.
The latest version available is UberWriter 15.05.01, which brings fixes only.
The latest UberWriter builds are available via PPA, so installing it on Ubuntu 15.04 is a piece of cake. All you need to do is add the PPA to your system, update the local repository index and install the uberwriter package:
$ sudo add-apt-repository ppa:w-vollprecht/ppa
$ sudo apt-get update
$ sudo apt-get install uberwriter
Optional, if you are not happy with uberwriter and want to remove it, do:
$ sudo apt-get remove uberwriter