make firefox web app profiles based on profile "webapp.template" with installed firefox-gnome-theme (https://github.com/rafaelmardojai/firefox-gnome-theme)

make-web-app

#!/bin/bash

PROFILES=$HOME/.mozilla/firefox
TEMPLATE_DIR=$PROFILES/webapp.template

usage() {
  cat << EOF
make-web-app
  -n name (e.g. twitter, used as profile name and wm class webapp.twitter)
  -t title (e.g. Twitter)
  -i icon url (e.g. https://abs.twimg.com/.../icon-default-large.8e027b65.png)
  -k keep old profile (false by default)
  -c use custom user chrome (default: none)

EOF
  echo profiles directory:
  echo "  " $PROFILES
  cd $PROFILES
  echo installed web apps:
  echo "  " webapp.*
  cd $TEMPLATE_DIR/chrome/customChromes
  echo custom chromes:
  echo "  " *
}

[ $# -eq 0 ] && usage && exit

while getopts "hn:t:i:c:k" opt; do
  case $opt in
    h) usage && exit
    ;;
    n) APP_NAME="$OPTARG"
    ;;
    t) APP_TITLE="$OPTARG"
    ;;
    i) ICON_URL="$OPTARG"
    ;;
    c) USER_CHROME="$OPTARG"
    ;;
    k) KEEP_OLD_PROFILE=1
    ;;
    \?) echo "Invalid option -$OPTARG" >&2
    ;;
  esac
done

shift $(($OPTIND - 1))

PROFILE_NAME="webapp.$APP_NAME"
PROFILE_DIR=$PROFILES/$PROFILE_NAME

[ ! -z "$ICON_URL" ] && {
  ICON_FILE="$HOME/.local/share/icons/$PROFILE_NAME.png"

  if [ -f $ICON_URL ]; then
    cp $ICON_URL $ICON_FILE
  else
    wget -O $ICON_FILE $ICON_URL
  fi
}

! ((KEEP_OLD_PROFILE)) && [ -d $PROFILE_DIR ] && rm -rf $PROFILE_DIR


[ ! -d $PROFILE_DIR ] && {
  cp -r $TEMPLATE_DIR $PROFILE_DIR
}


((KEEP_OLD_PROFILE)) || {
  echo "please set your desired website as the home page" \
    "and optionally set up the search engine"

  firefox --class $PROFILE_NAME --profile $PROFILE_DIR --no-remote \
    about:preferences#home
}

# remove old chrome
rm -rf $PROFILE_DIR/chrome/*

# link new chrome
ln -s $TEMPLATE_DIR/chrome/* $PROFILE_DIR/chrome

[ -n "$USER_CHROME" ] && {
  cd $PROFILE_DIR/chrome
  ln -s customChromes/$USER_CHROME.css customChrome.css
}

tee $HOME/.local/share/applications/$PROFILE_NAME.desktop << EOF
#!/usr/bin/env xdg-open
[Desktop Entry]
Version=1.0
Name=$APP_TITLE
Description=Firefox web app for $APP_TITLE
Exec=firefox --class $PROFILE_NAME --profile $PROFILE_DIR --no-remote
StartupWMClass=$PROFILE_NAME
Icon=$PROFILE_NAME
Terminal=false
Type=Application
Categories=GTK;Network;
StartupNotify=true
EOF