Index: debian/neon-settings.neon-update-kf5-snap.service
===================================================================
--- /dev/null
+++ debian/neon-settings.neon-update-kf5-snap.service
@@ -0,0 +1,15 @@
+[Unit]
+Description=Remove kde-frameworks-5 snap if it is unused
+ConditionPathExists=!/var/lib/neon/update-kf5-snap
+Requisite=snapd.service
+After=snapd.service
+
+[Service]
+Type=oneshot
+ExecStart=/usr/lib/neon_update/kf5_snap.rb
+ExecStart=/bin/mkdir -p /var/lib/neon/
+ExecStart=/usr/bin/touch /var/lib/neon/update-kf5-snap
+ExecStart=/bin/systemctl disable neon-update-kf5-snap.service
+
+[Install]
+WantedBy=snapd.service
Index: debian/rules
===================================================================
--- debian/rules
+++ debian/rules
@@ -10,12 +10,15 @@
 
 override_dh_systemd_enable:
 	dh_systemd_enable --name neon-update-calamares-groups
+	dh_systemd_enable --name neon-update-kf5-snap
 	dh_systemd_enable --name setvtrgb
 
 override_dh_systemd_start:
 	dh_systemd_start --no-start neon-update-calamares-groups.service
+	dh_systemd_start --no-start neon-update-kf5-snap.service
 	dh_systemd_start --no-start setvtrgb.service
 
 override_dh_installinit:
 	dh_installinit --noscripts --name neon-update-calamares-groups
+	dh_installinit --noscripts --name neon-update-kf5-snap
 	dh_installinit --noscripts --name setvtrgb
Index: usr/lib/neon_update/kf5_snap.rb
===================================================================
--- /dev/null
+++ usr/lib/neon_update/kf5_snap.rb
@@ -0,0 +1,99 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+#
+# Copyright (C) 2019 Harald Sitter <sitter@kde.org>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 3 of
+# the License or any later version accepted by the membership of
+# KDE e.V. (or its successor approved by the membership of KDE
+# e.V.), which shall act as a proxy defined in Section 14 of
+# version 3 of the license.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+require 'json'
+require 'net/http'
+require 'socket'
+
+SOCKET_PATH = '/run/snapd.socket'
+
+class APIResponse
+  attr_reader :type
+  attr_reader :status_code
+  attr_reader :status
+  attr_reader :result
+
+  def initialize(json)
+    @type = json.fetch('type')
+    @status_code = json.fetch('status-code')
+    @status = json.fetch('status')
+    @result = json.fetch('result')
+  end
+end
+
+class Connection
+  def initialize
+    @socket = Net::BufferedIO.new(UNIXSocket.new(SOCKET_PATH))
+  end
+
+  # @return returns the (not-parsed) json reply obj
+  def get(path)
+    request = Net::HTTP::Get.new(path)
+    request['host'] = 'localhost'
+    request.exec(@socket, '1.1', path)
+
+    response = nil
+    loop do
+      response = Net::HTTPResponse.read_new(@socket)
+      break unless response.is_a?(Net::HTTPContinue)
+    end
+    response.reading_body(@socket, request.response_body_permitted?) {}
+
+    yield response if block_given?
+
+    response
+  end
+end
+
+unless File.exist?(SOCKET_PATH)
+  warn 'snapd not running ➜ no clean-up of kde-frameworks-5 snap'
+  exit 0
+end
+
+# Get a list of all slot interfaces of kf5 and record snaps connected to it.
+# If none are connected that means the snap is unused and can be thrown out
+# under the assumption that the reason it is installed is because it was seeded
+# on the ISO.
+kf5_used_by = []
+Connection.new.get('/v2/interfaces') do |response|
+  response = JSON.parse(response.body)
+  response = APIResponse.new(response)
+
+  slots = response.result.fetch('slots')
+  kf5_slots = slots.find_all { |x| x.fetch('snap') == 'kde-frameworks-5' }
+
+  if kf5_slots.empty?
+    puts 'kde-frameworks-5 snap not installed; nothing to clean up.'
+    exit 0
+  end
+
+  kf5_slots.each do |slot|
+    connections = slot&.fetch('connections', [])
+    kf5_used_by += connections.collect { |x| x.fetch('snap') }
+  end
+end
+
+if kf5_used_by.empty?
+  puts 'kde-frameworks-5 snap used by nothing ➜ scheduling removal'
+  system('snap remove --no-wait kde-frameworks-5')
+else
+  puts "kde-frameworks-5 snap used by #{kf5_used_by} ➜ leaving it installed"
+end