diff --git a/packaging_apps_helpers.md b/packaging_apps_helpers.md
index eb087f80..72602ba2 100644
--- a/packaging_apps_helpers.md
+++ b/packaging_apps_helpers.md
@@ -2,85 +2,264 @@
 
 ## Shell helpers
 
-Since YunoHost 2.4 release, **new shell helpers** are available to ease packaging, in particular for common tasks like password generation, MySQL database creation…
+Since YunoHost 2.4 release, **new shell helpers** are available to ease common packaging tasks like password generation, MySQL database creation…
 
-Examples are available in the [example application](https://github.com/YunoHost/example_ynh/blob/master/scripts/install). We advise to use them. 
+Usage examples are available in the [example application](https://github.com/YunoHost/example_ynh/blob/master/scripts/install). We advise to use them.
 
 You can find them on this [repository](https://github.com/YunoHost/yunohost/blob/unstable/data/helpers.d).
 
 To use them, you need to add following lines in the shell scripts:
 ```bash
 # Source app helpers
-. /usr/share/yunohost/helpers
+source /usr/share/yunohost/helpers
 ```
 
-<!--
-<br />
+### Available helpers list (non exhaustive)
+#### Database
 
-#### Moulinette
-The CLI [moulinette](/moulinette) provides a few tools to make the packager's work easier:
+```bash
+ynh_mysql_execute_as_root SQL DB
+```
+
+> Runs the SQL command `SQL` as database root user on `DB` database (this last argument is optional).
+
+```bash
+ynh_mysql_execute_file_as_root FILE DB
+```
+
+> Runs the SQL commands listed inside `FILE` as root user on `DB` database (this last argument is optional).
+
+```bash
+ynh_mysql_create_db DB USER PWD
+```
+> Create the `DB` database and grants all rights to `USER` (created on the fly with `PASSWORD` password).
+
+```bash
+ynh_mysql_drop_db DB
+```
+> Delete the `DB` database.
+
+```bash
+ynh_mysql_dump_db DB > ./FILE
+```
+
+> Exports the `DB` database into the `FILE` file.
+
+#### Debian packages handling
+
+```bash
+ynh_package_is_installed PACKAGE
+```
+
+> Tests if the Debian package `PACKAGE` is installed on the system.
+    > Read command output to know the result. e.g:
+> ```bash
+> if ! ynh_package_is_installed "yunohost" ; then
+>   echo "Oops, package is not installed"
+> else
+>   echo "Package is installed"
+> fi
+> ```
+
+```bash
+ynh_package_version PACKAGE
+```
+> Returns the installed version number of `PACKAGE`.
+
+```bash
+ynh_package_update
+```
+> Updates the packages list (`apt update`) in a silent and non-interactive way.
+
+**Be careful, the following commands are to be avoided when possible. Installing (and even more removing) a package without handling conflicts and dependencies is risky. That will be improved in future Yunohost versions.**
+
+```bash
+ynh_package_install PACKAGE1 PACKAGE2
+```
+> Installs (`apt install`) `PACKAGE1`, `PACKAGE2`… packages, in a non interactive and silent way.
+
+```bash
+ynh_package_autoremove PACKAGE1 PACKAGE2
+```
+
+> Removes (`apt-get autoremove`) `PACKAGE1`, `PACKAGE2`… packages in a silent and non-interactive way.
+
+#### Apps configuration
+
+```bash
+ynh_app_setting_set APP KEY VALUE
+```
+
+> Store the setting named `KEY` with value `VALUE` for the app `APP`. This allows to reuse it later (typically in the `upgrade` script), or so that YunoHost can autoconfigure the SSO.
+> The settings are stored in the /etc/yunohost/apps/${APP}/settings.yml file.
+> For example, to store the visibility setting (private or public app), you can use :
+> ```bash
+> ynh_app_setting_set my_app is_public "yes"
+> ```
+
+The SSO uses app stored settings to allow or deny public access to HTTP resources. There are 6 configuration keys :
+
+`skipped_uris`, `unprotected_uris` and `protected_uris` are relative to app path. Example:
+> ```bash
+> ynh_app_setting_set app_name skipped_uris "/blog"
+> ```
+> Matches the /blog path of the application: https://domain.tld/path_app/blog and everything under this path, but not https://domain.tld/path_app/.
+
+**skipped_uris**
+An URL set with *skipped_uris* key will be totally ignored by the SSO, which means that the access will be public and the logged-in user information will not be passed to the app.
+
+**unprotected_uris**
+An URL set with *unprotected_uris* key will be accessible publicly, but if an user is logged in, his information will be accessible (though HTTP headers) to the app.
+
+**protected_uris**
+An URL set with *protected_uris* will be blocked by the SSO and accessible only to authenticated and authorized users.
+
+`skipped_regex`, `unprotected_uris` and `protected_regex` are regex counterparts of the above keys.
+
+> The syntax is **not** the "standard" regex syntax ([PCRE](https://en.wikipedia.org/wiki/Perl_Compatible_Regular_Expressions)) but [Lua patterns](http://lua-users.org/wiki/PatternsTutorial).
+
+The regex patterns match the whole URL, unlike the string patterns (which match only the app-local part of the URL, as detailed above). This means you must write complete patterns including the *domain* and *path*.
+> For example, to use *skipped_regex* to match /blog followed by a 1+ digit number:
+> ```bash
+> ynh_app_setting_set app_name skipped_regex "$domain$path/blog%?%d+$"
+> ```
+> This may lead to an issue : if $domain or $path contain a dash (-), it will interpreted as a pattern magic char. That is why dashes must be escaped with a %.
+> ```bash
+> domainregex=$(echo "$domain" | sed 's/-/\%&/g')
+> pathregex=$(echo "$path" | sed 's/-/\%&/g')
+> ynh_app_setting_set app_name skipped_regex "$domainregex$pathregex/blog%?%d+$"
+> ```
+
+```bash
+ynh_app_setting_get APP KEY
+```
+
+> Get the value of the setting named `KEY` for the `APP` app.
+> Example :
+> ```bash
+> is_public=$(ynh_app_setting_get app_name is_public)
+> ```
+
+
+```bash
+ynh_app_setting_delete APP KEY
+```
+
+Delete the setting named `KEY` for the `APP` app.
+
+#### Users management
+
+```bash
+ynh_user_exists USERNAME
+```
+
+> Checks the existence of `USERNAME` user in YunoHost.
+> Command return code must be checked to know the result.
+> Example:
+> ```bash
+> if ynh_user_exists "johndoe" ; then
+>   echo "This user exists!"
+> fi
+> ```
+```bash
+ynh_user_get_info USERNAME KEY
+```
+
+> Get the `KEY` information on `USERNAME` user.
+> Possible `KEY` values are:
+> - firstname
+> - fullname
+> - lastname
+> - mail
+> - mail-aliases
+> - mailbox-quota
+> Example:
+> ```bash
+> mailadmin=$(ynh_user_get_info $admin mail)
+> ```
+
+
+```bash
+ynh_system_user_exists USERNAME
+```
+> Checks if the `USERNAME` unix user exists.
+> Command return code must be checked to know the result.
+> Example:
+> ```bash
+> if ynh_system_user_exists "www-data" ; then
+>   echo "User exists on system!"
+> fi
+> ```
+
+
+#### Other commands
+```bash
+ynh_string_random LENGTH
+```
+> Generates a random string of `LENGTH` chars (defaults to 24).
+
+
+```bash
+ynh_die MSG RETCODE
+```
+> Displays the `MSG` message on stderr and exits the script with `RETCODE` return code (defaults to 1).
+
+<br/>
+
+**Following commands are to be replaced (or even deleted) in future YunoHost versions.**
 
 ```bash
 sudo yunohost app checkport <port>
 ```
-<blockquote>
-This helper checks the port and returns an error if the port is already in use.
-</blockquote>
+> This helper checks the port and returns an error if the port is already in use.
+> Command return code must be checked to know the result.
+> Example:
+> ```bash
+> port=DEFAULT_PORT
+> while ! sudo yunohost app checkport $port ; do
+>     port=$((port+1))
+> done
+> ```
 
-<br>
 
 ```bash
-sudo yunohost app setting <id> <key> [ -v <value> ]
+sudo yunohost firewall allow [--no-upnp] {TCP,UDP,Both} PORT
 ```
-<blockquote>
-This is the most important helper of YunoHost. It allows you to store some settings for a specific app, in order to be either reused afterward or used for YunoHost configuration (**e.g.** for the SSO).
-<br><br>
-It sets the value if you append ```-v <value>```, and gets it otherwise.
-<br><br>
-
-** Some useful settings **<br><br>
-```skipped_uris```<br><br>
-Remove the protection on the uris list provided separated by commas.<br><br>
-
-```protected_uris```<br><br>
-Protects the uris list provided separated by commas. Only logged in users will have access.<br><br>
-
-There are also `skipped_regex`, `protected_regex`, `unprotected_uris`, `unprotected_regex`.<br><br>
-
-**Be careful** : you must run `yunohost app ssowatconf` to apply the effect. URIs will be converted into URLs and written to the file /etc/ssowat/conf.json.<br><br>
-
-Example:<br>
-```yunohost app setting myapp unprotected_urls -v "/"```<br>
-```yunohost app ssowatconf```<br>
-These commands will disable the SSO on the root of the aplication like domain.tld/myapp This is useful for public application.
-</blockquote>
-
-<br>
+> Opens the port number `PORT` on the firewall, for TCP, UDP or both.
+> Automatic port opening via upnp may be disabled on this port using `--no-upnp`
 
 ```bash
-sudo yunohost app checkurl <domain><path> -a <id>
+sudo yunohost firewall disallow {TCP,UDP,Both} PORT
 ```
-<blockquote>
-This helper is useful for web apps and allows you to be sure that the web path is not taken by another app. If not, it "reserves" the path.
-<br><br>
-**Note**: do not prepend `http://` or `https://` to the `<domain><path>`.
-</blockquote>
-
-<br>
+> Closes the port number `PORT` on the firewall for TCP, UDP or both.
 
 ```bash
-sudo yunohost app initdb <db_user> [ -p <db_pwd> ] [ -s <SQL_file> ]
+sudo yunohost app checkurl DOMAINPATH -a APP
 ```
-<blockquote>
-This helper creates a MySQL database. If you do not append a password, it generates one and returns it. If you append a SQL file, it initializes your database with the SQL statements inside.
-</blockquote>
 
-<br>
+> Checks `DOMAIN`/`PATH` url availability. Useful for web apps to make sure the chosen URL is not already taken by another app. If the URL is available, that commands register for the `APP` application.
+> **Note**: do not prepend `http://` or `https://` to `DOMAINPATH`.
+
+
+```bash
+sudo yunohost app addaccess [--users=USER] APP
+```
+> Allow the `USER` user to access `APP`.
+
+
+```bash
+sudo yunohost app removeaccess --users=USER APP
+```
+> Remove the access authorization to `APP` from `USER` user.
+
+
+```bash
+sudo yunohost service remove NAME
+```
+> Remove the service `NAME` from the YunoHost management interface.
+
 
 ```bash
 sudo yunohost app ssowatconf
 ```
-<blockquote>
-This helper reloads the SSO configuration. You have to call it at the end of the script when you are packaging a web app.
-</blockquote>
--->
+> This commands rebuilds the SSO configuration. It is called automatically at the end of any script, but you may want to call it by hand before.