diff --git a/manifest.toml b/manifest.toml
index 2ef30ac..4e0bdea 100644
--- a/manifest.toml
+++ b/manifest.toml
@@ -53,47 +53,47 @@ ram.runtime = "50M"
     sha256 = "b1467797f892f72aa313f69f16d5277b481f2a7264ebe1d0ccf43311ca473684"
     autoupdate.strategy = "latest_github_release"
 
-    [resources.sources.upgrade_from_17]
+    [resources.sources.main_18_0_1]
     url = "https://github.com/dolibarr/dolibarr/archive/18.0.1.tar.gz"
     sha256 = "37bd3c8533b821c241dbb34b0e88349c1d5b43f7ffa6027f0b7970748d1f727a"
     prefetch = false
 
-    [resources.sources.upgrade_from_16]
+    [resources.sources.main_17_0_1]
     url = "https://github.com/dolibarr/dolibarr/archive/17.0.1.tar.gz"
     sha256 = "2eddd545c07eae291ad46e48ab55d3adb988d99c29a8dfaa2e2fde0a890b0ddc"
     prefetch = false
 
-    [resources.sources.upgrade_from_15]
+    [resources.sources.main_16_0_5]
     url = "https://github.com/dolibarr/dolibarr/archive/16.0.5.tar.gz"
     sha256 = "c8298342558e62b955a6f4c01fedb6a187b2e0c0b2c1681a97158ca979f9304f"
     prefetch = false
 
-    [resources.sources.upgrade_from_14]
+    [resources.sources.main_15_0_3]
     url = "https://github.com/dolibarr/dolibarr/archive/15.0.3.tar.gz"
     sha256 = "b145a38f56c44b166721d64909fb12408c6d10d08fcf74d2c00418a60201cc9d"
     prefetch = false
 
-    [resources.sources.upgrade_from_13]
+    [resources.sources.main_14_0_5]
     url = "https://github.com/Dolibarr/dolibarr/archive/14.0.5.tar.gz"
     sha256 = "31f4c934e484a9582d8867e4170f1f1acd8c41628b059370a6a449eb6e94ae75"
     prefetch = false
 
-    [resources.sources.upgrade_from_12]
+    [resources.sources.main_13_0_5]
     url = "https://github.com/Dolibarr/dolibarr/archive/13.0.5.tar.gz"
     sha256 = "08ec08dc5093d614361f273237f5aaf8d70e63d764c2fa8d7f3f68a1485156d0"
     prefetch = false
 
-    [resources.sources.upgrade_from_11]
+    [resources.sources.main_12_0_5]
     url = "https://github.com/Dolibarr/dolibarr/archive/12.0.5.tar.gz"
     sha256 = "b60b124ebcd294375f6200cc0683449e475b5dec687f8317b820fc8ec1413d21"
     prefetch = false
 
-    [resources.sources.upgrade_from_10]
+    [resources.sources.main_11_0_5]
     url = "https://github.com/Dolibarr/dolibarr/archive/11.0.5.tar.gz"
     sha256 = "6f51435a4ffe576e836bf6449d900de9a56016f09591322cb2ba47a07c97679d"
     prefetch = false
 
-    [resources.sources.upgrade_from_9]
+    [resources.sources.main_10_0_7]
     url = "https://github.com/Dolibarr/dolibarr/archive/10.0.7.tar.gz"
     sha256 = "6efc230f400a7b7152a0e4b9ba02a780f38b869b4aebd2bc28883268270ef871"
     prefetch = false
diff --git a/scripts/backup b/scripts/backup
index 97adcfe..3f87dc4 100755
--- a/scripts/backup
+++ b/scripts/backup
@@ -19,6 +19,13 @@ ynh_print_info --message="Declaring files to be backed up..."
 
 ynh_backup --src_path="$install_dir"
 
+#=================================================
+# BACKUP THE DATA DIR
+#=================================================
+
+### Only relevant if there is a "data_dir" resource for this app
+ynh_backup --src_path="$data_dir" --is_big
+
 #=================================================
 # BACKUP THE SYSTEM CONFIGURATION
 #=================================================
diff --git a/scripts/install b/scripts/install
index ee3c04b..e0f53bc 100644
--- a/scripts/install
+++ b/scripts/install
@@ -21,7 +21,6 @@ fpm_usage="medium"
 ynh_script_progression --message="Storing installation settings..." --weight=2
 
 ynh_app_setting_set --app="$app" --key="member" --value="$member"
-ynh_app_setting_set --app="$app" --key="version" --value="$(ynh_app_upstream_version)"
 ynh_app_setting_set --app="$app" --key="fpm_footprint" --value="$fpm_footprint"
 ynh_app_setting_set --app="$app" --key="fpm_usage" --value="$fpm_usage"
 
@@ -41,14 +40,15 @@ ynh_script_progression --message="Setting up source files..." --weight=1
 ynh_setup_source --dest_dir="$install_dir"
 
 chmod 750 "$install_dir"
+chmod -R o-rwx "$install_dir"
 chown -R "$app:www-data" "$install_dir"
 
 #=================================================
 # PREPARE AND INSTALL APP
 #=================================================
-ynh_script_progression --message="Adding a configuration file..." --weight=1
+ynh_script_progression --message="Adding $app's configuration file..." --weight=1
 
-ynh_add_config --template="conf.php" --destination="$install_dir/htdocs/conf/conf.php"
+ynh_add_config --template="../conf/conf.php" --destination="$install_dir/htdocs/conf/conf.php"
 
 chmod 644 "$install_dir/htdocs/conf/conf.php"
 chown "$app:$app" "$install_dir/htdocs/conf/conf.php"
diff --git a/scripts/remove b/scripts/remove
index 1a73be4..f617b28 100644
--- a/scripts/remove
+++ b/scripts/remove
@@ -8,9 +8,9 @@ source _common.sh
 source /usr/share/yunohost/helpers
 
 #=================================================
-# REMOVE NGINX CONFIGURATION
+# REMOVE SYSTEM CONFIGURATIONS
 #=================================================
-ynh_script_progression --message="Removing NGINX web server configuration..." --weight=1
+ynh_script_progression --message="Removing system configurations related to $app..." --weight=1
 
 # Remove the dedicated nginx config
 ynh_remove_nginx_config
diff --git a/scripts/restore b/scripts/restore
index af99308..9163735 100755
--- a/scripts/restore
+++ b/scripts/restore
@@ -15,8 +15,12 @@ ynh_script_progression --message="Restoring the app main directory..." --weight=
 
 ynh_restore_file --origin_path="$install_dir"
 
+# Set permissions on app files
 chmod 750 "$install_dir"
-chown -R $app:www-data "$install_dir"
+chmod -R o-rwx "$install_dir"
+chown -R "$app:www-data" "$install_dir"
+
+chmod 644 "$install_dir/htdocs/conf/conf.php"
 
 #=================================================
 # RESTORE THE DATA DIRECTORY
@@ -42,9 +46,6 @@ ynh_script_progression --message="Restoring system configurations related to $ap
 # Restore the file first, so it can have a backup if different
 ynh_restore_file --origin_path="/etc/php/$phpversion/fpm/pool.d/$app.conf"
 
-# Recreate a dedicated php-fpm config
-ynh_add_fpm_config --usage=$fpm_usage --footprint=$fpm_footprint
-
 ynh_restore_file --origin_path="/etc/nginx/conf.d/$domain.d/$app.conf"
 
 ynh_restore_file --origin_path="/etc/logrotate.d/$app"
@@ -54,8 +55,8 @@ ynh_restore_file --origin_path="/etc/logrotate.d/$app"
 #=================================================
 ynh_script_progression --message="Reloading NGINX web server and PHP-FPM..." --weight=1
 
-ynh_systemd_action --service_name=nginx --action=reload
 ynh_systemd_action --service_name="php$phpversion-fpm" --action=reload
+ynh_systemd_action --service_name=nginx --action=reload
 
 #=================================================
 # END OF SCRIPT
diff --git a/scripts/upgrade b/scripts/upgrade
index 3fcaa8b..78ddfa6 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -7,19 +7,6 @@
 source _common.sh
 source /usr/share/yunohost/helpers
 
-#=================================================
-# LOAD SETTINGS
-#=================================================
-
-update_version=$(ynh_app_upstream_version "../manifest.json")
-current_version=$(ynh_app_setting_get --app=$app --key=version)
-
-#=================================================
-# CHECK VERSION
-#=================================================
-
-upgrade_type=$(ynh_check_app_version_changed)
-
 #=================================================
 # STANDARD UPGRADE STEPS
 #=================================================
@@ -30,13 +17,21 @@ ynh_script_progression --message="Ensuring downward compatibility..." --weight=1
 # If fpm_footprint doesn't exist, create it
 if [ -z "${fpm_footprint:-}" ]; then
     fpm_footprint=low
-    ynh_app_setting_set --app=$app --key=fpm_footprint --value=$fpm_footprint
+    ynh_app_setting_set --app="$app" --key=fpm_footprint --value=$fpm_footprint
 fi
 
 # If fpm_usage doesn't exist, create it
 if [ -z "${fpm_usage:-}" ]; then
     fpm_usage=low
-    ynh_app_setting_set --app=$app --key=fpm_usage --value=$fpm_usage
+    ynh_app_setting_set --app="$app" --key=fpm_usage --value=$fpm_usage
+fi
+
+charset=$(mysql -ss -N -e "SELECT default_character_set_name FROM information_schema.SCHEMATA WHERE schema_name = '$db_name'")
+if [ "$charset" != "utf8" ]; then
+    ynh_print_info --message="Changing Database charset to utf8"
+    ynh_mysql_execute_as_root --sql="ALTER DATABASE $db_name charset=utf8"
+    ynh_local_curl  "/install/repair.php" "force_utf8_on_tables=confirmed" > "/var/log/$app/repair.html"
+    ynh_exec_fully_quiet sleep 5
 fi
 
 #=================================================
@@ -48,7 +43,7 @@ ynh_script_progression --message="Upgrading NGINX web server configuration..." -
 ynh_add_nginx_config
 
 # Recreate a dedicated PHP-FPM config
-ynh_add_fpm_config --usage=$fpm_usage --footprint=$fpm_footprint
+ynh_add_fpm_config --usage="$fpm_usage" --footprint="$fpm_footprint"
 
 #=================================================
 # SPECIFIC UPGRADE
@@ -56,113 +51,55 @@ ynh_add_fpm_config --usage=$fpm_usage --footprint=$fpm_footprint
 # MAKE SEQUENTIAL UPGRADES FROM EACH MAJOR
 # VERSION TO THE NEXT ONE
 #=================================================
-if [ "$upgrade_type" == "UPGRADE_APP" ]
-then
-	ynh_script_progression --message="Upgrading source files..." --weight=60
+ynh_script_progression --message="Upgrading source files..." --weight=60
 
-	# Load the last available version
-    source upgrade.d/upgrade.last.sh
-    last_version=$next_version
+upgrade_dolibarr() {
+    ynh_setup_source --source_id="$source_id" --dest_dir="$install_dir"
+    chmod -R o-rwx "$install_dir"
+    chown -R "$app:www-data" "$install_dir"
 
-	last_major_version=${last_version%%.*}
+    # Remove the lock if it exists
+    lock=$install_dir/documents/install.lock
+    if [ -f "$lock" ]; then
+        ynh_secure_remove --file="$lock"
+    fi
 
-	# While the current version is not the last version, do an upgrade
-    while [ "$last_version" != "$current_version" ]
-    do
+    pushd "$install_dir/htdocs/install/"
+        "php$phpversion" upgrade.php "$current_version" "$new_version"
+        ynh_exec_fully_quiet sleep 5
 
-		# The major version is the first part of the version number
-        current_major_version=${current_version%%.*}
+        "php$phpversion" upgrade2.php "$current_version" "$new_version"
+        ynh_exec_fully_quiet sleep 5
 
-        if [ ! -f upgrade.d/upgrade.$current_major_version.sh ]; then
-			source_id="main"
-        else
-			source_id="upgrade_from_$current_major_version"
-        fi
+        "php$phpversion" step5.php "$current_version" "$new_version"
+        ynh_exec_fully_quiet sleep 5
+    popd
+}
 
-		# If the current version has the same major version than the next one,
-        # then it's the last upgrade to do
-        # We also cover the case where the last version is the first of the current major version series
-        # (e.g. 20.0.0 is the latest version)
-        if [[ ("$last_major_version" -eq "$current_major_version") || ( ("$last_major_version" -eq "$((current_major_version+1))") && ("$next_version" == "$last_version") ) ]]; then
-            current_major_version=last
-        fi
+# Sort --version-sort cdécembrean handle underscore in versions numbers
+mapfile -t main_versions < <(
+    ynh_read_manifest --key="resources.sources | keys[]" | grep "main_" | sort --version-sort
+)
+current_version="$YNH_APP_CURRENT_VERSION"
+for version in "${main_versions[@]}"; do
+    new_version=$(echo "$version" | sed 's|main_||' | sed 's|_|.|g')
+    if dpkg --compare-versions "$current_version" ge "$new_version"; then
+        continue
+    fi
+    ynh_print_info --message="Upgrading app from $current_version to $new_version"
+    upgrade_dolibarr
+    current_version="$new_version"
+done
 
-		# Load the value for this version
-        source upgrade.d/upgrade.$current_major_version.sh
+# Final upgrade to the final version
+new_version=$(ynh_app_upstream_version)
+ynh_print_info --message="Upgrading app from $current_version to $new_version"
+upgrade_dolibarr
 
-		ynh_print_info --message="Upgrading app from $current_version to $next_version"
-		# Download, check integrity, uncompress and patch the source from app.src
-		ynh_setup_source --source_id="$source_id" --dest_dir="$install_dir"
-
-		chown -R $app: "$install_dir"
-
-		# Remove the lock if it exists
-		lock=$install_dir/documents/install.lock
-		if [ -f $lock ]
-		then
-			ynh_secure_remove $lock
-		fi
-
-		mkdir -p /var/log/$app/
-
-		# Upgrade with CURL
-
-		charset=$(mysql -ss -N -e "SELECT default_character_set_name FROM information_schema.SCHEMATA WHERE schema_name = '$db_name'")
-		if [ "$charset" != "utf8" ]
-		then
-			ynh_print_info --message="Changing Database charset to utf8"
-
-			ynh_mysql_execute_as_root --database=$db_name --sql="ALTER DATABASE $db_name charset=utf8"
-
-			ynh_local_curl  "/install/repair.php" \
-					"force_utf8_on_tables=confirmed" > /var/log/$app/repair.html
-		fi
-
-		ynh_exec_fully_quiet sleep 5
-
-
-		# Download, check integrity, uncompress and patch the source from app.src
-		ynh_setup_source --dest_dir="$install_dir"
-
-		pushd $install_dir/htdocs/install/
-
-		if php$phpversion upgrade.php $current_version $next_version > /var/log/$app/upgrade.html;  then
-			ynh_print_info --message="Step 1 upgrading ended successfully"
-		else
-			ynh_die --message="Step 1 upgrading ended with error"
-		fi
-
-			ynh_exec_fully_quiet sleep 5
-
-			if php$phpversion upgrade2.php $current_version $next_version > /var/log/$app/upgrade2.html; then
-				ynh_print_info --message="Step 2 upgrading ended successfully"
-			else
-				ynh_die --message="Step 2 upgrading ended with error"
-			fi
-
-			ynh_exec_fully_quiet sleep 5
-
-			if php$phpversion step5.php $current_version $next_version > /var/log/$app/upgrade3.html; then
-				ynh_print_info --message="Step 3 upgrading ended successfully"
-			else
-				ynh_die  --message="Step 3 upgrading ended with error"
-			fi
-		popd
-
-
-		# Get the new current version number
-        current_version=$next_version
-        current_major_version=${current_version%%.*}
-
-		done
-
-		if php$phpversion $install_dir/scripts/user/sync_users_ldap2dolibarr.php commitiferror --server=localhost -y; then
-				ynh_print_info --message="LDAP user update ok"
-		else
-				ynh_print_info --message="LDAP user update ended with error"
-		fi
-
-		ynh_app_setting_set --app=$app --key=version --value=$update_version
+if "php$phpversion" "$install_dir/scripts/user/sync_users_ldap2dolibarr.php" commitiferror --server=localhost -y; then
+    ynh_print_info --message="LDAP user update ok"
+else
+    ynh_print_info --message="LDAP user update ended with error"
 fi
 
 #=================================================
@@ -191,9 +128,9 @@ ynh_script_progression --message="Configuring permissions..." --weight=1
 
 # Set permissions on app files
 if [ ! -f "$data_dir/install.lock" ]; then
-	echo 'This is a lock file to prevent use of install pages (set with permission 440)' > "$data_dir/install.lock"
-	chown $app:$app "$data_dir/install.lock"
-	chmod 440 "$data_dir/install.lock"
+    echo 'This is a lock file to prevent use of install pages (set with permission 440)' > "$data_dir/install.lock"
+    chown $app:$app "$data_dir/install.lock"
+    chmod 440 "$data_dir/install.lock"
 fi
 
 chmod 750 "$install_dir"