FocusWriter is a text editor, having a hide-away interface to provide a distraction-free environment. It is open-source and cross-plaftorm, working on Linux, Windows and Mac OS X. Among others, it has support for TXT, RTF and ODT, allows the users to set timers and alarms, it has auto-save and spell-check, it supports some new themes and is traslated in more than 20 languages.
The latest version available is FocusWriter 1.6.16, which has been recently released, coming with a few fixes only:
The latest FocusWriter builds are available via some third party PPA, so installing it is easy. All you need to do is add the PPA to your system, update the local repository index and install the focuswriter package. Like this:
$ sudo add-apt-repository ppa:gottcode/gcppa
$ sudo apt-get update
$ sudo apt-get install focuswriter
Optional, to remove focuswriter, do:
$ sudo apt-get remove focuswriter
The installation instructions should work on Ubuntu 18.10 Cosmic Cuttlefish, Ubuntu 18.04 Bionic Beaver, Linux Mint, Elementary OS and other Ubuntu derivative systems.