diff --git a/scripts/install b/scripts/install
index fdcdc26..6c77d73 100644
--- a/scripts/install
+++ b/scripts/install
@@ -1,51 +1,83 @@
 #!/bin/bash
 
-# Exit on command errors and treat unset variables as an error
-set -eu
-
-app="movim"
-
-# Retrieve arguments
-domain=$1
-path=${2:-/}
-admin=$3
-password=$4
-language=$5
-ssoenabled=$6
-port=$7
-timezone=`cat /etc/timezone`
-
-# Source local helpers
-source ./_common.sh
+#=================================================
+# GENERIC START
+#=================================================
+# IMPORT GENERIC HELPERS
+#=================================================
 
+source _common.sh
 source /usr/share/yunohost/helpers
 
-# Check domain/path availability
-sudo yunohost app checkurl "${domain}${path}" -a "$app" \
-  || exit 1
+#=================================================
+# MANAGE SCRIPT FAILURE
+#=================================================
+
+# Exit if an error occurs during the execution of the script
+ynh_abort_if_errors
+
+#=================================================
+# RETRIEVE ARGUMENTS FROM THE MANIFEST
+#=================================================
+
+domain=$YNH_APP_ARG_DOMAIN
+path_url=$YNH_APP_ARG_PATH
+admin=$YNH_APP_ARG_ADMIN
+password=$YNH_APP_ARG_PASSWORD
+language=$YNH_APP_ARG_LANGUAGE
+ssoenabled=$YNH_APP_ARG_SSOENABLED
+port=$YNH_APP_ARG_PORT
+timezone=$(cat /etc/timezone)
+
+### If it's a multi-instance app, meaning it can be installed several times independently
+### The id of the app as stated in the manifest is available as $YNH_APP_ID
+### The instance number is available as $YNH_APP_INSTANCE_NUMBER (equals "1", "2", ...)
+### The app instance name is available as $YNH_APP_INSTANCE_NAME
+###    - the first time the app is installed, YNH_APP_INSTANCE_NAME = ynhexample
+###    - the second time the app is installed, YNH_APP_INSTANCE_NAME = ynhexample__2
+###    - ynhexample__{N} for the subsequent installations, with N=3,4, ...
+### The app instance name is probably what interests you most, since this is
+### guaranteed to be unique. This is a good unique identifier to define installation path,
+### db names, ...
+app=$YNH_APP_INSTANCE_NAME
+
+#=================================================
+# CHECK IF THE APP CAN BE INSTALLED WITH THESE ARGS
+#=================================================
+
+# TODO: final_path=/var/www/$app
+test ! -e "$DESTDIR" || ynh_die "This path already contains a folder"
+
+# Normalize the url path syntax
+path_url=$(ynh_normalize_url_path $path_url)
+
+# Check web path availability
+ynh_webpath_available $domain $path_url
+# Register (book) web path
+ynh_webpath_register $app $domain $path_url
 
 # Check port availability
-sudo yunohost app checkport "$port" \
-  || exit 1
+yunohost app checkport "$port" \
+  || ynh_die "This port is already used"
 
-# Check user availability
-ynh_user_exists "$admin" \
-  || ynh_die "The chosen admin user does not exist."
-
-# Check password not empty
-[[ -n "$password" ]] \
-  || ynh_die "You must set an admin password."
-
-# Check timezone
-[[ -n "$timezone" ]] \
-  || ynh_die "Could not detect timezone, please check /etc/timezone." \
-  && echo "Detected timezone: $timezone"
+#=================================================
+# STORE SETTINGS FROM MANIFEST
+#=================================================
 
 # Save app settings
 ynh_app_setting_set "$app" admin "$admin"
 ynh_app_setting_set "$app" ssoenabled "$ssoenabled"
 ynh_app_setting_set "$app" port "$port"
-ynh_app_setting_set "$app" path "$path"
+ynh_app_setting_set "$app" path "$path_url"
+
+
+#=================================================
+# STANDARD MODIFICATIONS
+#=================================================
+
+#=================================================
+# CREATE A MYSQL DATABASE
+#=================================================
 
 # Generate and save random MySQL password
 db_pwd=$(ynh_string_random 12)
@@ -58,9 +90,17 @@ db_name=movim
 # Create MySQL database
 ynh_mysql_create_db "$db_name" "$db_user" "$db_pwd"
 
+#=================================================
+# INSTALL DEPENDENCIES
+#=================================================
+
 # Install packages
 ynh_install_app_dependencies php5-gd php5-curl php5-imagick php5-cli php5-zmq
 
+#=================================================
+# DOWNLOAD, CHECK AND UNPACK SOURCE
+#=================================================
+
 # Download Movim source code
 tmp_path=/tmp/movim-git
 sudo rm -rf "$tmp_path"
@@ -68,21 +108,35 @@ sudo rm -rf "$tmp_path"
    && cd "$tmp_path" && git checkout "$HEAD_COMMIT") \
   || ynh_die "Unable to download Movim source code."
 
+#=================================================
+# SET CONFIGURATION FILE
+#=================================================
+
+# TODO: add checksum
 # Set database configuration
 cp "${tmp_path}/config/"{db.example.inc.php,db.inc.php}
 sed -i "s@'username'    => 'username'@'username'    => '$db_user'@g" \
     "${tmp_path}/config/db.inc.php"
 sed -i "s@'password'    => 'password'@'password'    => '$db_pwd'@g" \
     "${tmp_path}/config/db.inc.php"
-## FIXME: consider installation in a subpath
-sed -i "s@'/ws/'@'${path%/}/ws/'@g" \
+## TODO: consider installation in a subpath
+sed -i "s@'/ws/'@'${path_url%/}/ws/'@g" \
     "${tmp_path}/app/assets/js/movim_websocket.js"
 
 # Move Movim source code
 sudo mv "$tmp_path" "$DESTDIR"
 
+#=================================================
+# CREATE DEDICATED USER
+#=================================================
+
 # Create movim system user and set permissions
 sudo useradd -d /var/www/movim -s /bin/sh movim
+
+#=================================================
+# SET PERMISSIONS
+#=================================================
+
 sudo chown -R movim:www-data "$DESTDIR"
 sudo find "${DESTDIR}/" -type f -print0 | sudo xargs -0 chmod 0644
 sudo find "${DESTDIR}/" -type d -print0 | sudo xargs -0 chmod 0755
@@ -95,14 +149,23 @@ sudo chmod 400 "${DESTDIR}/config/db.inc.php"
  && exec_cmd php composer.phar install --no-interaction) \
   || ynh_die "Unable to install Movim dependencies."
 
+
+#=================================================
+# Set Movim database and configuration
+#=================================================
+
 # Set Movim database and configuration
 exec_cmd php mud.php db --set
 exec_cmd php mud.php config --loglevel=1 \
     --locale="$language" --timezone="$timezone" \
     --username="$admin" --password="$password"
 
+#=================================================
+# SETUP SYSTEMD
+#=================================================
+
 # Copy init script or systemd service
-sudo sed -i "s@YHURL@${domain}${path}@g" ../conf/movim.{service,init}
+sudo sed -i "s@YHURL@${domain}${path_url}@g" ../conf/movim.{service,init}
 sudo sed -i "s@YHDIR@${DESTDIR}@g" ../conf/movim.{service,init}
 sudo sed -i "s@YHPORT@${port}@g" ../conf/movim.{service,init}
 if [ -d /run/systemd/system ]; then
@@ -117,17 +180,35 @@ else
     sudo /etc/init.d/movim start
 fi
 
+#=================================================
+# PHP-FPM CONFIGURATION
+#=================================================
+
 # php-fpm configuration
 sed -i "s@YHTZ@$timezone@g" ../conf/php-fpm.conf
 sudo cp ../conf/php-fpm.conf /etc/php5/fpm/pool.d/movim.conf
 
+#=================================================
+# NGINX CONFIGURATION
+#=================================================
+
 # Nginx configuration
-sed -i "s@PATHTOCHANGE@$path@g" ../conf/nginx.conf
+sed -i "s@PATHTOCHANGE@$path_url@g" ../conf/nginx.conf
 sed -i "s@ALIASTOCHANGE@$DESTDIR/@g" ../conf/nginx.conf
 sed -i "s@YHPORT@$port@g" ../conf/nginx.conf
 sed -i "s@//ws/@/ws/@g" ../conf/nginx.conf # Avoid duplicate /
 sudo cp ../conf/nginx.conf /etc/nginx/conf.d/$domain.d/movim.conf
 
+
+#=================================================
+# GENERIC FINALIZATION
+#=================================================
+
+
+#=================================================
+# SETUP SSOWAT
+#=================================================
+
 # SSOwat configuration
 if [[ "$ssoenabled" = "No" ]]; then
     ynh_app_setting_set "$app" skipped_uris "/"
@@ -137,6 +218,10 @@ else
     apply_sso_patch
 fi
 
+#=================================================
+# RELOAD NGINX
+#=================================================
+
 # Reload services
 sudo service php5-fpm restart
 sudo service nginx reload
diff --git a/scripts/remove b/scripts/remove
index 2bd9960..6b8b50a 100644
--- a/scripts/remove
+++ b/scripts/remove
@@ -1,24 +1,45 @@
 #!/bin/bash
 
-app="movim"
-
-# Source local helpers
-source ./_common.sh
+#=================================================
+# GENERIC START
+#=================================================
+# IMPORT GENERIC HELPERS
+#=================================================
 
+source _common.sh
 source /usr/share/yunohost/helpers
 
+#=================================================
+# LOAD SETTINGS
+#=================================================
+
+app=$YNH_APP_INSTANCE_NAME
+
 # Retrieve app settings
 domain=$(ynh_app_setting_get "$app" domain)
 
-# Remove nginx and php-fpm configuration files
+#=================================================
+# REMOVE NGINX CONFIGURATION
+#=================================================
+
+# Remove the dedicated nginx config
 sudo rm -f "/etc/nginx/conf.d/${domain}.d/movim.conf"
+
+#=================================================
+# REMOVE PHP-FPM CONFIGURATION
+#=================================================
+
+# Remove the dedicated php-fpm config
 sudo rm -f "/etc/php5/fpm/pool.d/movim.conf"
 
 # Reload services
 sudo service nginx reload
 sudo service php5-fpm restart
 
-# Stop service and remove it
+#=================================================
+# STOP AND REMOVE SERVICE
+#=================================================
+
 sudo service movim stop
 if [ -d /run/systemd/system ]; then
     sudo systemctl --quiet disable movim.service
@@ -36,13 +57,26 @@ fi
 # Remove metapackage and its dependencies
 ynh_remove_app_dependencies
 
-# Drop MySQL database and user
+#=================================================
+# REMOVE THE MYSQL DATABASE
+#=================================================
+
 db_user=movim
 db_name=movim
 ynh_mysql_drop_db "$db_name" || true
 ynh_mysql_drop_user "$db_user" || true
 
-# Remove Movim files and user
+#=================================================
+# REMOVE APP MAIN DIR
+#=================================================
+
 sudo rm -rf /var/www/movim
+
+#=================================================
+# GENERIC FINALIZATION
+#=================================================
+# REMOVE DEDICATED USER
+#=================================================
+
 ynh_system_user_exists movim \
   && sudo userdel movim
diff --git a/scripts/upgrade b/scripts/upgrade
index 603d936..e37c592 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -1,31 +1,65 @@
 #!/bin/bash
 
-# Exit on command errors and treat unset variables as an error
-set -eu
-
-app="movim"
-
-# Source local helpers
-source ./_common.sh
+#=================================================
+# GENERIC START
+#=================================================
+# IMPORT GENERIC HELPERS
+#=================================================
 
+source _common.sh
 source /usr/share/yunohost/helpers
 
+#=================================================
+# LOAD SETTINGS
+#=================================================
+
+app=$YNH_APP_INSTANCE_NAME
+
 # Retrieve app settings
 domain=$(ynh_app_setting_get "$app" domain)
-path=$(ynh_app_setting_get "$app" path)
+path_url=$(ynh_app_setting_get "$app" path)
 port=$(ynh_app_setting_get "$app" port)
 ssoenabled=$(ynh_app_setting_get "$app" ssoenabled)
 public_site=$(ynh_app_setting_get "$app" public_site)
-timezone=`cat /etc/timezone`
+timezone=$(cat /etc/timezone)
 
-# Check timezone
-[[ -n "$timezone" ]] \
-  || ynh_die "Could not detect timezone, please check /etc/timezone." \
-  && echo "Detected timezone: $timezone"
+#=================================================
+# ACTIVE TRAP
+#=================================================
+
+# TODO: activate backup
+# Backup the current version of the app
+# ynh_backup_before_upgrade
+# ynh_clean_setup () {
+	# restore it if the upgrade fails
+	# ynh_restore_upgradebackup
+# }
+# Exit if an error occurs during the execution of the script
+ynh_abort_if_errors
+
+#=================================================
+# CHECK THE PATH
+#=================================================
+
+# Normalize the URL path syntax
+path_url=$(ynh_normalize_url_path $path_url)
+
+
+#=================================================
+# STANDARD UPGRADE STEPS
+#=================================================
+
+#=================================================
+# UPGRADE DEPENDENCIES
+#=================================================
 
 # Since Movim 0.13, zmq is required
 ynh_install_app_dependencies php5-zmq
 
+#=================================================
+# DOWNLOAD, CHECK AND UNPACK SOURCE
+#=================================================
+
 # Init git repository as needed
 if [ ! -d "${DESTDIR}/.git" ]; then
     tmp_path=/tmp/movim-git
@@ -51,26 +85,47 @@ fi
 (exec_cmd git fetch origin \
    && exec_cmd git reset --hard "$HEAD_COMMIT") \
   || ynh_die "Unable to download Movim source code."
-## FIXME: consider installation in a subpath
-exec_cmd sed -i "s@'/ws/'@'${path%/}/ws/'@g" \
+## TODO: consider installation in a subpath
+exec_cmd sed -i "s@'/ws/'@'${path_url%/}/ws/'@g" \
     "${DESTDIR}/app/assets/js/movim_websocket.js"
 
+#=================================================
+# CREATE DEDICATED USER
+#=================================================
+
 # Create movim user if not exists and set permissions
 ynh_system_user_exists movim \
   || sudo useradd -d /var/www/movim -s /bin/sh movim
+
+#=================================================
+# SET PERMISSIONS
+#=================================================
+
 sudo chown -R movim:www-data "$DESTDIR"
 sudo find "${DESTDIR}/" -type f -print0 | sudo xargs -0 chmod 0644
 sudo find "${DESTDIR}/" -type d -print0 | sudo xargs -0 chmod 0755
 sudo chmod 400 "${DESTDIR}/config/db.inc.php"
 
+#=================================================
+# install PHP dependencies
+#=================================================
+
 # Update PHP dependencies using composer
 (exec_cmd php composer.phar config --global discard-changes true \
  && exec_cmd php composer.phar install --no-interaction) \
   || ynh_die "Unable to update Movim dependencies."
 
+#=================================================
+# Upgrade Movim Databas
+#=================================================
+
 # Upgrade Movim database as needed
 exec_cmd php mud.php db --set
 
+#=================================================
+# ENSURE DOWNWARD COMPATIBILITY
+#=================================================
+
 # Reset SSO parameters
 ynh_app_setting_delete "$app" protected_uris
 ynh_app_setting_delete "$app" skipped_uris
@@ -85,6 +140,10 @@ if [ ! -z "$public_site" ]; then
     ynh_app_setting_set "$app" ssoenabled "$ssoenabled"
 fi
 
+#=================================================
+# SETUP SSOWAT
+#=================================================
+
 # SSOwat configuration
 if [[ "$ssoenabled" = "No" ]]; then
     ynh_app_setting_set "$app" skipped_uris "/"
@@ -95,8 +154,13 @@ else
     apply_sso_patch
 fi
 
+
+#=================================================
+# SETUP SYSTEMD
+#=================================================
+
 # Update init scripts
-sudo sed -i "s@YHURL@${domain}${path}@g" ../conf/movim.{service,init}
+sudo sed -i "s@YHURL@${domain}${path_url}@g" ../conf/movim.{service,init}
 sudo sed -i "s@YHDIR@${DESTDIR}@g" ../conf/movim.{service,init}
 sudo sed -i "s@YHPORT@${port}@g" ../conf/movim.{service,init}
 if [ -d /run/systemd/system ]; then
@@ -111,17 +175,29 @@ else
     sudo /etc/init.d/movim start
 fi
 
+#=================================================
+# PHP-FPM CONFIGURATION
+#=================================================
+
 # Update php-fpm configuration
 sed -i "s@YHTZ@$timezone@g" ../conf/php-fpm.conf
 sudo cp ../conf/php-fpm.conf /etc/php5/fpm/pool.d/movim.conf
 
+#=================================================
+# NGINX CONFIGURATION
+#=================================================
+
 # Nginx configuration
-sed -i "s@PATHTOCHANGE@$path@g" ../conf/nginx.conf
+sed -i "s@PATHTOCHANGE@$path_url@g" ../conf/nginx.conf
 sed -i "s@ALIASTOCHANGE@$DESTDIR/@g" ../conf/nginx.conf
 sed -i "s@YHPORT@$port@g" ../conf/nginx.conf
 sed -i "s@//ws/@/ws/@g" ../conf/nginx.conf # Avoid duplicate /
 sudo cp ../conf/nginx.conf /etc/nginx/conf.d/$domain.d/movim.conf
 
+#=================================================
+# RELOAD SERVICES
+#=================================================
+
 # Reload services
 sudo service movim restart
 sudo service php5-fpm restart