Solution 1:

The following worked on my system:

sudo apt-get install snapd
sudo snap install notes

I needed to log out and then back in for Dash to find 'Notes':

enter image description here

Note: There is currently some confusion with another Xenial package called snap which gives: 'location of genes from DNA sequence with hidden markov model'. If you get dpkg errors to do with this package when installing snapd (in particular overwriting of commonly named man pages) run the following:

sudo apt-get purge snap

And then you should be right to go :)

The application 'Notes' was perhaps a little underwhelming, other packages look a little more promising:

andrew@athens:~$ snap find
Name                   Version                  Summary
audovia                3.2.2                    Database application for making music using JFugue MusicStrings
beagleblack            3.1                      OEM Beagle Bone Black
canonical-dragon       0.7.1                    The gadget snap for the dragonboard
canonical-i386         3.1.i386                 The gadget snap for generic i386 systems
canonical-pc           3.2                      AMD64 generic package
canonical-pc-linux     4.4.0-18+20160419.13-26  The ubuntu-core kernel snap
canonical-pi2          3.2                      Raspberry Pi 2 support package
go-example-webserver   16.04-4                  Minimal Golang webserver for snappy
hello-world            6.0                      Hello world example
http                   4.6692016                HTTPie in a snap
john-the-ripper        1.8.0-11765-g9a09113     John the Ripper Jumbo password cracker for Linux
links                  2.12-1                   Web browser running in text mode
moon-buggy             1.0.51.9                 Drive a car across the moon
morse-converter-py     1-2                      Simple command-line Morse converter
nmap                   7.12SVN-0.4              Nmap ("Network Mapper") is a free and open source utility for network discovery and security auditing
notes                  0.0.8~snap3.gita80fd1c   Note-taking application, write down your thoughts
shout                  0.53.0                   A self hosted web IRC client
sshtron                1.0                      multiplayer Tron via ssh
tmux                   2.3bump1                 tmux
tor-middle-relay       0.2.7.6-6                Essential infrastructure node for Tor network
ubuntu-calculator-app  2.1+snap3                Ubuntu Calculator application for the Unity 7 desktop
ubuntu-clock-app       3.6+snap3                Ubuntu Clock application for the Unity 7 desktop
ubuntu-core            16.04+20160419.20-55     The ubuntu-core OS snap
xkcd-webserver         16.04-5                  Show random XKCD compic via a build-in webserver
yacas                  1.4.2                    Yet Another Computer Algebra System

Interesting times ahead...

Solution 2:

There are 4 steps:

  1. sudo rm /etc/apt/preferences.d/nosnap.pref

  2. sudo apt update

  3. sudo apt install snapd

Then, install whatever you need, for example:

  1. sudo snap install rocketchat-desktop or sudo snap install notes