diff --git a/scripts/_common.sh b/scripts/_common.sh
index 51dc46f..e230fac 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -4,9 +4,9 @@
 # COMMON VARIABLES
 #=================================================
 # dependencies used by the app
-YNH_PHP_VERSION="7.3"
+YNH_PHP_VERSION="7.4"
 
-extra_php_dependencies="php${YNH_PHP_VERSION}-sqlite3"
+extra_php_dependencies="php${YNH_PHP_VERSION}-sqlite3 php${YNH_PHP_VERSION}-bz2 php${YNH_PHP_VERSION}-imap php${YNH_PHP_VERSION}-json php${YNH_PHP_VERSION}-intl php${YNH_PHP_VERSION}-curl php${YNH_PHP_VERSION}-zip"
 
 #=================================================
 # PERSONAL HELPERS
@@ -15,7 +15,343 @@ extra_php_dependencies="php${YNH_PHP_VERSION}-sqlite3"
 #=================================================
 # EXPERIMENTAL HELPERS
 #=================================================
+# Install another version of php.
+#
+# usage: ynh_install_php --phpversion=phpversion [--package=packages]
+# | arg: -v, --phpversion - Version of php to install.
+# | arg: -p, --package - Additionnal php packages to install
+ynh_install_php () {
+  # Declare an array to define the options of this helper.
+  local legacy_args=vp
+  declare -Ar args_array=( [v]=phpversion= [p]=package= )
+  local phpversion
+  local package
+  # Manage arguments with getopts
+  ynh_handle_getopts_args "$@"
+  package=${package:-}
 
+  # Store phpversion into the config of this app
+  ynh_app_setting_set $app phpversion $phpversion
+
+  if [ "$phpversion" == "7.3" ]
+  then
+    ynh_die "Do not use ynh_install_php to install php7.3"
+  fi
+
+  # Store the ID of this app and the version of php requested for it
+  echo "$YNH_APP_INSTANCE_NAME:$phpversion" | tee --append "/etc/php/ynh_app_version"
+  # Add an extra repository for those packages
+  ynh_install_extra_repo --repo="https://packages.sury.org/php/ $(lsb_release -sc) main" --key="https://packages.sury.org/php/apt.gpg" --priority=995 --name=extra_php_version
+
+  # Install requested dependencies from this extra repository.
+  # Install php-fpm first, otherwise php will install apache as a dependency.
+  ynh_add_app_dependencies --package="php${phpversion}-fpm"
+  ynh_add_app_dependencies --package="php$phpversion php${phpversion}-common $package"
+
+  # Set php7.3 back as the default version for php-cli.
+  update-alternatives --set php /usr/bin/php7.3
+
+  # Pin this extra repository after packages are installed to prevent sury of doing shit
+  ynh_pin_repo --package="*" --pin="origin \"packages.sury.org\"" --priority=200 --name=extra_php_version
+  ynh_pin_repo --package="php7.3*" --pin="origin \"packages.sury.org\"" --priority=600 --name=extra_php_version --append
+  # Advertise service in admin panel
+  yunohost service add php${phpversion}-fpm --log "/var/log/php${phpversion}-fpm.log"
+}
+# Remove the specific version of php used by the app.
+#
+# usage: ynh_install_php
+ynh_remove_php () {
+  # Get the version of php used by this app
+  local phpversion=$(ynh_app_setting_get $app phpversion)
+  if [ "$phpversion" == "7.3" ] || [ -z "$phpversion" ]
+  then
+    if [ "$phpversion" == "7.3" ]
+    then
+      ynh_print_err "Do not use ynh_remove_php to install php7.3"
+    fi
+    return 0
+  fi
+  # Remove the line for this app
+  sed --in-place "/$YNH_APP_INSTANCE_NAME:$phpversion/d" "/etc/php/ynh_app_version"
+  # If no other app uses this version of php, remove it.
+  if ! grep --quiet "$phpversion" "/etc/php/ynh_app_version"
+  then
+    # Purge php dependences for this version.
+    ynh_package_autopurge "php$phpversion php${phpversion}-fpm php${phpversion}-common"
+    # Remove the service from the admin panel
+    yunohost service remove php${phpversion}-fpm
+  fi
+  # If no other app uses alternate php versions, remove the extra repo for php
+  if [ ! -s "/etc/php/ynh_app_version" ]
+  then
+    ynh_secure_remove /etc/php/ynh_app_version
+  fi
+}
+#=================================================
+# FUTURE OFFICIAL HELPERS
+#=================================================
+# Pin a repository.
+#
+# usage: ynh_pin_repo --package=packages --pin=pin_filter [--priority=priority_value] [--name=name] [--append]
+# | arg: -p, --package - Packages concerned by the pin. Or all, *.
+# | arg: -i, --pin - Filter for the pin.
+# | arg: -p, --priority - Priority for the pin
+# | arg: -n, --name - Name for the files for this repo, $app as default value.
+# | arg: -a, --append - Do not overwrite existing files.
+#
+# See https://manpages.debian.org/stretch/apt/apt_preferences.5.en.html for information about pinning.
+#
+ynh_pin_repo () {
+  # Declare an array to define the options of this helper.
+  local legacy_args=pirna
+  declare -Ar args_array=( [p]=package= [i]=pin= [r]=priority= [n]=name= [a]=append )
+  local package
+  local pin
+  local priority
+  local name
+  local append
+  # Manage arguments with getopts
+  ynh_handle_getopts_args "$@"
+  package="${package:-*}"
+  priority=${priority:-50}
+  name="${name:-$app}"
+  append=${append:-0}
+  if [ $append -eq 1 ]
+  then
+    append="tee -a"
+  else
+    append="tee"
+  fi
+  mkdir -p "/etc/apt/preferences.d"
+  echo "Package: $package
+Pin: $pin
+Pin-Priority: $priority
+" \
+  | $append "/etc/apt/preferences.d/$name"
+}
+
+# Add a repository.
+#
+# usage: ynh_add_repo --uri=uri --suite=suite --component=component [--name=name] [--append]
+# | arg: -u, --uri - Uri of the repository.
+# | arg: -s, --suite - Suite of the repository.
+# | arg: -c, --component - Component of the repository.
+# | arg: -n, --name - Name for the files for this repo, $app as default value.
+# | arg: -a, --append - Do not overwrite existing files.
+#
+# Example for a repo like deb http://forge.yunohost.org/debian/ stretch stable
+#                             uri                               suite   component
+# ynh_add_repo --uri=http://forge.yunohost.org/debian/ --suite=stretch --component=stable
+#
+ynh_add_repo () {
+  # Declare an array to define the options of this helper.
+  local legacy_args=uscna
+  declare -Ar args_array=( [u]=uri= [s]=suite= [c]=component= [n]=name= [a]=append )
+  local uri
+  local suite
+  local component
+  local name
+  local append
+  # Manage arguments with getopts
+  ynh_handle_getopts_args "$@"
+  name="${name:-$app}"
+  append=${append:-0}
+  if [ $append -eq 1 ]
+  then
+    append="tee -a"
+  else
+    append="tee"
+  fi
+  mkdir -p "/etc/apt/sources.list.d"
+  # Add the new repo in sources.list.d
+  echo "deb $uri $suite $component" \
+    | $append "/etc/apt/sources.list.d/$name.list"
+}
+# Add an extra repository correctly, pin it and get the key.
+#
+# usage: ynh_install_extra_repo --repo="repo" [--key=key_url] [--priority=priority_value] [--name=name] [--append]
+# | arg: -r, --repo - Complete url of the extra repository.
+# | arg: -k, --key - url to get the public key.
+# | arg: -p, --priority - Priority for the pin
+# | arg: -n, --name - Name for the files for this repo, $app as default value.
+# | arg: -a, --append - Do not overwrite existing files.
+ynh_install_extra_repo () {
+  # Declare an array to define the options of this helper.
+  local legacy_args=rkpna
+  declare -Ar args_array=( [r]=repo= [k]=key= [p]=priority= [n]=name= [a]=append )
+  local repo
+  local key
+  local priority
+  local name
+  local append
+  # Manage arguments with getopts
+  ynh_handle_getopts_args "$@"
+  name="${name:-$app}"
+  append=${append:-0}
+  key=${key:-0}
+  priority=${priority:-}
+  if [ $append -eq 1 ]
+  then
+    append="--append"
+    wget_append="tee -a"
+  else
+    append=""
+    wget_append="tee"
+  fi
+  # Split the repository into uri, suite and components.
+  # Remove "deb " at the beginning of the repo.
+  repo="${repo#deb }"
+  # Get the uri
+  local uri="$(echo "$repo" | awk '{ print $1 }')"
+  # Get the suite
+  local suite="$(echo "$repo" | awk '{ print $2 }')"
+  # Get the components
+  local component="${repo##$uri $suite }"
+  # Add the repository into sources.list.d
+  ynh_add_repo --uri="$uri" --suite="$suite" --component="$component" --name="$name" $append
+  # Pin the new repo with the default priority, so it won't be used for upgrades.
+  # Build $pin from the uri without http and any sub path
+  local pin="${uri#*://}"
+  pin="${pin%%/*}"
+  # Set a priority only if asked
+  if [ -n "$priority" ]
+  then
+    priority="--priority=$priority"
+  fi
+  ynh_pin_repo --package="*" --pin="origin \"$pin\"" $priority --name="$name" $append
+  # Get the public key for the repo
+  if [ -n "$key" ]
+  then
+    mkdir -p "/etc/apt/trusted.gpg.d"
+    wget -q "$key" -O - | gpg --dearmor | $wget_append /etc/apt/trusted.gpg.d/$name.gpg > /dev/null
+  fi
+  # Update the list of package with the new repo
+  ynh_package_update
+}
+# Remove an extra repository and the assiociated configuration.
+#
+# usage: ynh_remove_extra_repo [--name=name]
+# | arg: -n, --name - Name for the files for this repo, $app as default value.
+ynh_remove_extra_repo () {
+  # Declare an array to define the options of this helper.
+  local legacy_args=n
+  declare -Ar args_array=( [n]=name= )
+  local name
+  # Manage arguments with getopts
+  ynh_handle_getopts_args "$@"
+  name="${name:-$app}"
+  ynh_secure_remove "/etc/apt/sources.list.d/$name.list"
+  ynh_secure_remove "/etc/apt/preferences.d/$name"
+  ynh_secure_remove "/etc/apt/trusted.gpg.d/$name.gpg"
+  ynh_secure_remove "/etc/apt/trusted.gpg.d/$name.asc"
+  # Update the list of package to exclude the old repo
+  ynh_package_update
+}
+# Install packages from an extra repository properly.
+#
+# usage: ynh_install_extra_app_dependencies --repo="repo" --package="dep1 dep2" [--key=key_url] [--name=name]
+# | arg: -r, --repo - Complete url of the extra repository.
+# | arg: -p, --package - The packages to install from this extra repository
+# | arg: -k, --key - url to get the public key.
+# | arg: -n, --name - Name for the files for this repo, $app as default value.
+ynh_install_extra_app_dependencies () {
+  # Declare an array to define the options of this helper.
+  local legacy_args=rpkn
+  declare -Ar args_array=( [r]=repo= [p]=package= [k]=key= [n]=name= )
+  local repo
+  local package
+  local key
+  local name
+  # Manage arguments with getopts
+  ynh_handle_getopts_args "$@"
+  name="${name:-$app}"
+  key=${key:-0}
+  # Set a key only if asked
+  if [ -n "$key" ]
+  then
+    key="--key=$key"
+  fi
+  # Add an extra repository for those packages
+  ynh_install_extra_repo --repo="$repo" $key --priority=995 --name=$name
+  # Install requested dependencies from this extra repository.
+  ynh_add_app_dependencies --package="$package"
+  # Remove this extra repository after packages are installed
+  ynh_remove_extra_repo --name=$app
+}
+#=================================================
+# patched version of ynh_install_app_dependencies to be used with ynh_add_app_dependencies
+# Define and install dependencies with a equivs control file
+# This helper can/should only be called once per app
+#
+# usage: ynh_install_app_dependencies dep [dep [...]]
+# | arg: dep - the package name to install in dependence
+#   You can give a choice between some package with this syntax : "dep1|dep2"
+#   Example : ynh_install_app_dependencies dep1 dep2 "dep3|dep4|dep5"
+#   This mean in the dependence tree : dep1 & dep2 & (dep3 | dep4 | dep5)
+#
+# Requires YunoHost version 2.6.4 or higher.
+ynh_install_app_dependencies () {
+    local dependencies=$@
+    dependencies="$(echo "$dependencies" | sed 's/\([^\<=\>]\)\ \([^(]\)/\1, \2/g')"
+    dependencies=${dependencies//|/ | }
+    local manifest_path="../manifest.json"
+    if [ ! -e "$manifest_path" ]; then
+      manifest_path="../settings/manifest.json" # Into the restore script, the manifest is not at the same place
+    fi
+    local version=$(grep '\"version\": ' "$manifest_path" | cut -d '"' -f 4)  # Retrieve the version number in the manifest file.
+    if [ ${#version} -eq 0 ]; then
+        version="1.0"
+    fi
+    local dep_app=${app//_/-} # Replace all '_' by '-'
+    # Handle specific versions
+    if [[ "$dependencies" =~ [\<=\>] ]]
+    then
+        # Replace version specifications by relationships syntax
+        # https://www.debian.org/doc/debian-policy/ch-relationships.html
+        # Sed clarification
+        # [^(\<=\>] ignore if it begins by ( or < = >. To not apply twice.
+        # [\<=\>] matches < = or >
+        # \+ matches one or more occurence of the previous characters, for >= or >>.
+        # [^,]\+ matches all characters except ','
+        # Ex: package>=1.0 will be replaced by package (>= 1.0)
+        dependencies="$(echo "$dependencies" | sed 's/\([^(\<=\>]\)\([\<=\>]\+\)\([^,]\+\)/\1 (\2 \3)/g')"
+    fi
+    cat > /tmp/${dep_app}-ynh-deps.control << EOF # Make a control file for equivs-build
+Section: misc
+Priority: optional
+Package: ${dep_app}-ynh-deps
+Version: ${version}
+Depends: ${dependencies}
+Architecture: all
+Description: Fake package for $app (YunoHost app) dependencies
+ This meta-package is only responsible of installing its dependencies.
+EOF
+    ynh_package_install_from_equivs /tmp/${dep_app}-ynh-deps.control \
+        || ynh_die --message="Unable to install dependencies" # Install the fake package and its dependencies
+    rm /tmp/${dep_app}-ynh-deps.control
+    ynh_app_setting_set --app=$app --key=apt_dependencies --value="$dependencies"
+}
+ynh_add_app_dependencies () {
+  # Declare an array to define the options of this helper.
+  local legacy_args=pr
+  declare -Ar args_array=( [p]=package= [r]=replace)
+  local package
+  local replace
+  # Manage arguments with getopts
+  ynh_handle_getopts_args "$@"
+  replace=${replace:-0}
+  local current_dependencies=""
+  if [ $replace -eq 0 ]
+  then
+    local dep_app=${app//_/-} # Replace all '_' by '-'
+    if ynh_package_is_installed --package="${dep_app}-ynh-deps"
+    then
+      current_dependencies="$(dpkg-query --show --showformat='${Depends}' ${dep_app}-ynh-deps) "
+    fi
+    current_dependencies=${current_dependencies// | /|}
+  fi
+  ynh_install_app_dependencies "${current_dependencies}${package}"
+}
 #=================================================
 # FUTURE OFFICIAL HELPERS
 #=================================================
diff --git a/scripts/install b/scripts/install
index 9ff666a..c735ca8 100644
--- a/scripts/install
+++ b/scripts/install
@@ -46,6 +46,14 @@ ynh_script_progression --message="Storing installation settings..." --weight=1
 ynh_app_setting_set --app=$app --key=domain --value=$domain
 ynh_app_setting_set --app=$app --key=path --value=$path_url
 
+#=================================================
+# INSTALL DEPENDENCIES
+#=================================================
+ynh_script_progression --message="Installing dependencies..." --weight=10
+
+ynh_install_app_dependencies $pkg_dependencies
+ynh_install_php --phpversion="$php_version" --package="$extra_pkg_dependencies"
+
 #=================================================
 # CREATE DEDICATED USER
 #=================================================
@@ -77,7 +85,7 @@ ynh_add_nginx_config
 ynh_script_progression --message="Configuring PHP-FPM..." --weight=5
 
 # Create a dedicated PHP-FPM config
-ynh_add_fpm_config --package="$extra_php_dependencies"
+ynh_add_fpm_config --phpversion=$YNH_PHP_VERSION --package="$extra_php_dependencies"
 phpversion=$(ynh_app_setting_get --app=$app --key=phpversion)
 
 #=================================================
diff --git a/scripts/remove b/scripts/remove
index 7780ced..3f0c7d7 100644
--- a/scripts/remove
+++ b/scripts/remove
@@ -41,7 +41,7 @@ ynh_remove_nginx_config
 ynh_script_progression --message="Removing PHP-FPM configuration..." --weight=2
 
 # Remove the dedicated PHP-FPM config
-ynh_remove_fpm_config --package="$extra_php_dependencies"
+ynh_remove_fpm_config --phpversion=$YNH_PHP_VERSION --package="$extra_php_dependencies"
 
 #=================================================
 # GENERIC FINALIZATION
diff --git a/scripts/restore b/scripts/restore
index 5d3be8e..f23b8ad 100644
--- a/scripts/restore
+++ b/scripts/restore
@@ -76,7 +76,7 @@ ynh_script_progression --message="Reconfiguring PHP-FPM..." --weight=6
 
 ynh_restore_file --origin_path="/etc/php/$phpversion/fpm/pool.d/$app.conf"
 
-ynh_add_fpm_config --package="$extra_php_dependencies"
+ynh_add_fpm_config --phpversion=$YNH_PHP_VERSION --package="$extra_php_dependencies"
 
 #=================================================
 # GENERIC FINALIZATION
diff --git a/scripts/upgrade b/scripts/upgrade
index d3ecff8..b2d87eb 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -162,7 +162,7 @@ ynh_add_nginx_config
 ynh_script_progression --message="Upgrading PHP-FPM configuration..." --weight=2
 
 # Create a dedicated PHP-FPM config
-ynh_add_fpm_config --package="$extra_php_dependencies"
+ynh_add_fpm_config --phpversion=$YNH_PHP_VERSION --package="$extra_php_dependencies"
 phpversion=$(ynh_app_setting_get --app=$app --key=phpversion)
 #=======================================================
 # backup bdd, squelettes directory and config.local.php