diff --git a/.gitignore b/.gitignore
index da3509e3f..1ede2b5c7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,4 +9,4 @@ raspbian_boot
 ncp-web/wizard.cfg
 ncp-web/ncp-web.cfg
 docker-armhf/qemu-arm-static
-.vagrant/
+.vagrant/
\ No newline at end of file
diff --git a/bin/ncp/CONFIG/nc-autoupdate-nc.sh b/bin/ncp/CONFIG/nc-autoupdate-nc.sh
index 8cfa1375b..079740d24 100644
--- a/bin/ncp/CONFIG/nc-autoupdate-nc.sh
+++ b/bin/ncp/CONFIG/nc-autoupdate-nc.sh
@@ -23,8 +23,8 @@ configure()
   cat > /etc/cron.daily/ncp-autoupdate-nc <<EOF
 #!/bin/bash
 
-echo -e "[ncp-update-nc]"                          >> /var/log/ncp.log
-/usr/local/bin/ncp-update-nc "$VERSION" 2>&1 | tee -a /var/log/ncp.log
+echo -e "[ncp-update-nc]"                          >> /var/log/ncp/ncp.log
+/usr/local/bin/ncp-update-nc "$VERSION" 2>&1 | tee -a /var/log/ncp/ncp.log
 
 if [[ \${PIPESTATUS[0]} -eq 0 ]]; then
 
@@ -33,7 +33,7 @@ if [[ \${PIPESTATUS[0]} -eq 0 ]]; then
   sudo -u www-data php /var/www/nextcloud/occ notification:generate \
     "$NOTIFYUSER" "NextCloudPi" -l "Nextcloud was updated to \$VER"
 fi
-echo "" >> /var/log/ncp.log
+echo "" >> /var/log/ncp/ncp.log
 EOF
   chmod 755 /etc/cron.daily/ncp-autoupdate-nc
   echo "automatic Nextcloud updates enabled"
diff --git a/bin/ncp/CONFIG/nc-update-nc-apps-auto.sh b/bin/ncp/CONFIG/nc-update-nc-apps-auto.sh
index 95466161f..c08aa8cd2 100644
--- a/bin/ncp/CONFIG/nc-update-nc-apps-auto.sh
+++ b/bin/ncp/CONFIG/nc-update-nc-apps-auto.sh
@@ -20,9 +20,9 @@ configure()
 
   cat > "$cronfile" <<'EOF'
 #!/bin/bash
-echo "[ nc-update-nc-apps-auto ]" >> /var/log/ncp.log
-echo "checking for updates..."    >> /var/log/ncp.log
-ncc app:update --all -n           >> /var/log/ncp.log
+echo "[ nc-update-nc-apps-auto ]" >> /var/log/ncp/ncp.log
+echo "checking for updates..."    >> /var/log/ncp/ncp.log
+ncc app:update --all -n           >> /var/log/ncp/ncp.log
 EOF
   chmod 755 "$cronfile"
   echo "automatic app updates enabled"
diff --git a/etc/library.sh b/etc/library.sh
index 1b41fe2cc..d4c1abc6a 100644
--- a/etc/library.sh
+++ b/etc/library.sh
@@ -10,6 +10,8 @@
 
 CFGDIR=/usr/local/etc/ncp-config.d
 BINDIR=/usr/local/bin/ncp
+LOCK_FILE=/run/ncp.lock
+LOG=/var/log/ncp/ncp.log
 
 function configure_app()
 {
@@ -22,14 +24,16 @@ function configure_app()
   type dialog &>/dev/null || { echo "please, install dialog for interactive configuration"; return 1; }
   [[ -f "$cfg_file" ]]    || return 0;
 
-  local cfg="$( cat "$cfg_file" )"
-  local len="$(jq  '.params | length' <<<"$cfg")"
+  local cfg len
+  cfg="$( cat "$cfg_file" )"
+  len="$(jq  '.params | length' <<<"$cfg")"
   [[ $len -eq 0 ]] && return
 
   # read cfg parameters
   for (( i = 0 ; i < len ; i++ )); do
-    local var="$(jq -r ".params[$i].id"    <<<"$cfg")"
-    local val="$(jq -r ".params[$i].value" <<<"$cfg")"
+    local var val
+    var="$(jq -r ".params[$i].id"    <<<"$cfg")"
+    val="$(jq -r ".params[$i].value" <<<"$cfg")"
     local vars+=("$var")
     local vals+=("$val")
     local idx=$((i+1))
@@ -91,8 +95,9 @@ function configure_app()
 
 function run_app()
 {
-  local ncp_app=$1
-  local script="$(find "$BINDIR" -name $ncp_app.sh)"
+  local script ncp_app
+  ncp_app=$1
+  script="$(find "$BINDIR" -name "$ncp_app.sh")"
 
   [[ -f "$script" ]] || { echo "file $script not found"; return 1; }
 
@@ -102,42 +107,153 @@ function run_app()
 # receives a script file, no security checks
 function run_app_unsafe()
 {
-  local script=$1
-  local ncp_app="$(basename "$script" .sh)"
+  local script ncp_app
+  script=$1
+  ncp_app="$(basename "$script" .sh)"
   local cfg_file="$CFGDIR/$ncp_app.cfg"
-  local log=/var/log/ncp.log
 
   [[ -f "$script" ]] || { echo "file $script not found"; return 1; }
 
-  touch               $log
-  chmod 640           $log
-  chown root:www-data $log
+  touch               "$LOG"
+  chmod 640           "$LOG"
+  chown root:www-data "$LOG"
 
   echo "Running $ncp_app"
-  echo "[ $ncp_app ]" >> $log
 
-  # read script
+  attach_and_exit_if_running
+
   unset configure
-  source "$script"
+  (
+    # read cfg parameters
+    [[ -f "$cfg_file" ]] && {
+      local len cfg
+      cfg="$( cat "$cfg_file" )"
+      jq -e '.tmux' <<<"$cfg" &>/dev/null
+      local use_tmux="$?"
+      len="$(jq '.params | length' <<<"$cfg")"
+      for (( i = 0 ; i < len ; i++ )); do
+        local var val
+        var="$(jq -r ".params[$i].id"    <<<"$cfg")"
+        val="$(jq -r ".params[$i].value" <<<"$cfg")"
+        eval "export $var=$val"
+      done
+    }
+ 
+    echo "$ncp_app" > "$LOCK_FILE"
+    if which tmux > /dev/null && [[ $use_tmux == 0 ]]
+    then
+      run_app_in_tmux "$ncp_app" "$script"
+    else
+      # shellcheck disable=SC2064
+      trap "rm '$LOCK_FILE'" EXIT SIGHUP SIGINT SIGQUIT SIGILL SIGABRT SIGSEV SIGTERM SIGIO
+      echo "[ $ncp_app ]" | tee -a "$LOG"
+      echo "Closing the browser/terminal session will interrupt $ncp_app!" | tee -a "$LOG"
+      # read script
+      # shellcheck source=/dev/null
+      source "$script"
+      # run
+      configure 2>&1 | tee -a "$LOG"
+      local ret="${PIPESTATUS[0]}"
+      exit "$ret"
+    fi
+  )
+  ret="$?"
+  echo "" >> "$LOG"
 
-  # read cfg parameters
-  [[ -f "$cfg_file" ]] && {
-    local cfg="$( cat "$cfg_file" )"
-    local len="$(jq '.params | length' <<<"$cfg")"
-    for (( i = 0 ; i < len ; i++ )); do
-      local var="$(jq -r ".params[$i].id"    <<<"$cfg")"
-      local val="$(jq -r ".params[$i].value" <<<"$cfg")"
-      eval "$var=$val"
-    done
+  return "$ret"
+}
+
+function run_app_in_tmux()
+{
+  local ncp_app="$1"
+  local script="$2"
+
+  echo "You can safely exit. $ncp_app will keep running until it's done." | tee -a "$LOG"
+  echo "Reattach at any time by running the app again." | tee -a "$LOG"
+  # Run app in tmux
+  local tmux_log_file tmux_status_file LIBPATH
+  tmux_log_file="/var/log/ncp/tmux.${ncp_app}.log"
+  tmux_status_file="/var/log/ncp/tmux.${ncp_app}.status"
+  LIBPATH="$(dirname "$CFGDIR")/library.sh"
+  
+  # Reset tmux output
+  echo "[ $ncp_app ]" >> "$LOG"
+  echo "[ $ncp_app ]" > "$tmux_log_file"
+  echo "" > "$tmux_status_file"
+  chmod 640           "$tmux_log_file" "$tmux_status_file"
+  chown root:www-data "$tmux_log_file" "$tmux_status_file"
+
+  tmux new-session -d -s "$ncp_app" "bash -c '(
+    trap \"echo \\\$? > $tmux_status_file && rm $LOCK_FILE\" 1 2 3 4 6 9 11 15 19 29
+    source \"$LIBPATH\"
+    source \"$script\"
+    configure 2>&1 | tee -a \"$LOG\"
+    echo \"\${PIPESTATUS[0]}\" > $tmux_status_file
+    rm $LOCK_FILE
+  )' 2>&1 | tee -a $tmux_log_file"
+
+  attach_to_app "$ncp_app"
+  return $?
+}
+
+function attach_and_exit_if_running()
+{
+  # Check if app is already running in tmux
+  local running_app
+  running_app=$( [[ -f "$LOCK_FILE" ]] && cat "$LOCK_FILE" || echo "" )
+  [[ ! -z $running_app ]] && which tmux >/dev/null && tmux has-session -t="$running_app" &>/dev/null && {
+    
+    local choice question
+    [[ $ATTACH_TO_RUNNING == "1" ]] && choice="y"
+    [[ $ATTACH_TO_RUNNING == "0" ]] && choice="n"
+    question="An app ($running_app) is already running. Do you want to attach to it's output? <y/n> "
+    if [[ $choice == "y" ]] || [[ $choice == "n" ]]
+    then
+      echo "$question"
+      echo "Choice: <$choice>"
+    else
+      read -rp "$question" choice
+      while [[ "$choice" != "y" ]] && [[ "$choice" != "n" ]]
+      do
+        echo "choice was '$choice'"
+        read -rp "Invalid choice. y or n expected." choice
+      done
+    fi
+
+    if [[ "$choice" == "y" ]]
+    then
+      attach_to_app "$running_app"
+    fi
+    exit $?
   }
+  return 0
+}
 
-  # run
-  configure 2>&1 | tee -a $log
-  local ret="${PIPESTATUS[0]}"
+function attach_to_app()
+{
+  local tmux_log_file tmux_status_file
+  tmux_log_file="/var/log/ncp/tmux.${ncp_app}.log"
+  tmux_status_file="/var/log/ncp/tmux.${ncp_app}.status"
+
+  if [[ "$ATTACH_NO_FOLLOW" == "1" ]]
+  then
+    cat "$tmux_log_file"
+    return 0
+  else
+    (while tmux has-session -t="$ncp_app" > /dev/null 2>&1 
+    do
+      sleep 1
+    done) &
 
-  echo "" >> $log
+    # Follow log file until tmux session has terminated
+    tail --lines=+0 -f "$tmux_log_file" --pid="$!"
+  fi
 
-  return "$ret"
+  # Read return value from tmux log file
+  ret="$(tail -n 1 "$tmux_status_file")"
+
+  [[ $ret =~ ^[0-9]+$ ]] && return $ret
+  return 1
 }
 
 function is_active_app()
@@ -147,18 +263,20 @@ function is_active_app()
   local script="$bin_dir/$ncp_app.sh"
   local cfg_file="$CFGDIR/$ncp_app.cfg"
 
-  [[ -f "$script" ]] || local script="$(find "$BINDIR" -name $ncp_app.sh)"
+  [[ -f "$script" ]] || script="$(find "$BINDIR" -name $ncp_app.sh)"
   [[ -f "$script" ]] || { echo "file $script not found"; return 1; }
 
   # function
   unset is_active
+  # shellcheck source=/dev/null
   source "$script"
   [[ $( type -t is_active ) == function ]] && { is_active; return $?; }
 
   # config
   [[ -f "$cfg_file" ]] || return 1
 
-  local cfg="$( cat "$cfg_file" )"
+  local cfg
+  cfg="$( cat "$cfg_file" )"
   [[ "$(jq -r ".params[0].id"    <<<"$cfg")" == "ACTIVE" ]] && \
   [[ "$(jq -r ".params[0].value" <<<"$cfg")" == "yes"    ]] && \
   return 0
@@ -170,9 +288,10 @@ function info_app()
   local ncp_app=$1
   local cfg_file="$CFGDIR/$ncp_app.cfg"
 
-  local cfg="$( cat "$cfg_file" 2>/dev/null )"
-  local info=$( jq -r .info <<<"$cfg" )
-  local infotitle=$( jq -r .infotitle <<<"$cfg" )
+  local cfg info infotitle
+  cfg="$( cat "$cfg_file" 2>/dev/null )"
+  info=$( jq -r .info <<<"$cfg" )
+  infotitle=$( jq -r .infotitle <<<"$cfg" )
 
   [[ "$info"      == "" ]] || [[ "$info"      == "null" ]] && return 0
   [[ "$infotitle" == "" ]] || [[ "$infotitle" == "null" ]] && infotitle="Info"
@@ -187,18 +306,20 @@ function info_app()
 
 function install_app()
 {
+  local script
   local ncp_app=$1
 
   # $1 can be either an installed app name or an app script
   if [[ -f "$ncp_app" ]]; then
-    local script="$ncp_app"
-    local ncp_app="$(basename "$script" .sh)"
+    script="$ncp_app"
+    ncp_app="$(basename "$script" .sh)"
   else
-    local script="$(find "$BINDIR" -name $ncp_app.sh)"
+    script="$(find "$BINDIR" -name $ncp_app.sh)"
   fi
 
   # do it
   unset install
+  # shellcheck source=/dev/null
   source "$script"
   echo "Installing $ncp_app"
   (install)
@@ -208,6 +329,7 @@ function cleanup_script()
 {
   local script=$1
   unset cleanup
+  # shellcheck source=/dev/null
   source "$script"
   if [[ $( type -t cleanup ) == function ]]; then
     cleanup
diff --git a/ncp-web/js/ncp.js b/ncp-web/js/ncp.js
index 556bc90e6..33a372c37 100644
--- a/ncp-web/js/ncp.js
+++ b/ncp-web/js/ncp.js
@@ -25,8 +25,8 @@ window.onpopstate = function(event) {
     click_app($('#' + selectedID));
 };
 
-function errorMsg()
-{ 
+function errorMsg(e)
+{
   $('#config-box').fill( "Something went wrong. Try refreshing the page" ); 
 }
 
@@ -268,21 +268,36 @@ $(function()
         var ret = $.parseJSON( result );
         if ( ret.token )
           $('#csrf-token').set( { value: ret.token } );
-        if ( ret.ret )                           // means that the process was launched
+        if ( "ret" in ret )                           // means that the process was launched
         {
-          if ( ret.ret == '0' ) 
+          if ( ret.ret == 0 )
           {
             if( ret.ref && ret.ref == 'nc-update' )
               window.location.reload( true );
             reload_sidebar();
             $('.circle-retstatus').set('+icon-green-circle');
           }
-          else 
+          else if ( ret.ret === -1 ) // means we attach to an already running app
+          {
+            if( ret.output )
+            {
+              var box_l = $('#' + selectedID + '-details-box');
+              var box   = box_l[0];
+              var lines = ret.output.split("\n");
+              lines.forEach(line => {
+                box_l.ht( box.innerHTML + escapeHTML(line) + '<br>' );
+              });
+              box.scrollTop = box.scrollHeight;
+            }
             $('.circle-retstatus').set('-icon-green-circle');
+          }
+          else
+          {
+            $('.circle-retstatus').set('-icon-green-circle');
+          }
         }
         else                                     // print error from server instead
         {
-          $('.details-box').fill(ret.output);
           $('.circle-retstatus').set('-icon-green-circle');
         }
         $( 'input' , '#config-box-wrapper' ).set('@disabled', null);
diff --git a/ncp-web/ncp-launcher.php b/ncp-web/ncp-launcher.php
index 332450188..5e068b4ac 100644
--- a/ncp-web/ncp-launcher.php
+++ b/ncp-web/ncp-launcher.php
@@ -80,13 +80,30 @@
   }
 
   // launch
-  echo '{ "token": "' . getCSRFToken() . '",';     // Get new token
-  echo ' "ref": "' . $ncp_app          . '",';
-  echo ' "output": "" , ';
-  echo ' "ret": ';
 
-  exec( 'bash -c "sudo /home/www/ncp-launcher.sh ' . $ncp_app . '"' , $output , $ret );
-  echo '"' . $ret . '" }';
+  $lock_file = "/run/ncp.lock";
+  if( file_exists($lock_file) )
+  {
+    $running = trim(file_get_contents($lock_file));
+    $output = "An app ($running) is already running...".PHP_EOL;
+    if ( file_exists("/var/log/ncp/tmux.$running.log") )
+    {
+      $output .= "Attaching to its output:".PHP_EOL;
+      $output .= file_get_contents("/var/log/ncp/tmux.$running.log");
+    }
+    $ret = -1;
+  }
+  else
+  {
+    exec( 'sudo /home/www/ncp-launcher.sh ' . $ncp_app , $cmd_out , $ret );
+  }
+
+  echo json_encode(array(
+    "token" => getCSRFToken(),
+    "ref" => $ncp_app,
+    "output" => $output,
+    "ret" => $ret
+  ));
 }
 
 //
diff --git a/ncp-web/ncp-output.php b/ncp-web/ncp-output.php
index 704b0a581..f7083f529 100644
--- a/ncp-web/ncp-output.php
+++ b/ncp-web/ncp-output.php
@@ -79,7 +79,7 @@ function follow($file)
 session_write_close();
 echo str_pad('',1024*1024*4); // make sure the browser buffer becomes full
 
-$ncp_log = '/var/log/ncp.log';
+$ncp_log = '/var/log/ncp/ncp.log';
 if (!file_exists($ncp_log))
   touch($ncp_log);
 follow($ncp_log);
diff --git a/ncp.sh b/ncp.sh
index 71872fa35..533b960e7 100644
--- a/ncp.sh
+++ b/ncp.sh
@@ -14,6 +14,7 @@ BRANCH=master
 
 BINDIR=/usr/local/bin/ncp
 CONFDIR=/usr/local/etc/ncp-config.d/
+LOGFILE=/var/log/ncp/ncp.log
 APTINSTALL="apt-get install -y --no-install-recommends"
 export DEBIAN_FRONTEND=noninteractive
 
@@ -22,8 +23,13 @@ install()
 {
   # NCP-CONFIG
   apt-get update
-  $APTINSTALL git dialog whiptail jq
-  mkdir -p "$CONFDIR" "$BINDIR"
+  $APTINSTALL git dialog whiptail jq tmux locale
+  # Install UTF-8 locale required by tmux
+  grep -v '#' /etc/locale.gen | grep -ie "en_US.UTF-8[[:blank:]]*UTF-8" &> /dev/null || {
+    echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen
+    locale-gen
+  }
+  mkdir -p "$CONFDIR" "$BINDIR" "$(dirname LOGFILE)"
 
   # include option in raspi-config (only Raspbian)
   test -f /usr/bin/raspi-config && {
@@ -131,8 +137,9 @@ EOF
 
   cat > /home/www/ncp-launcher.sh <<'EOF'
 #!/bin/bash
+
 source /usr/local/etc/library.sh
-run_app $1
+run_app "$1"
 EOF
   chmod 700 /home/www/ncp-launcher.sh
   echo "www-data ALL = NOPASSWD: /home/www/ncp-launcher.sh , /sbin/halt, /sbin/reboot" >> /etc/sudoers
@@ -188,7 +195,7 @@ EOF
   # LIMIT LOG SIZE
   grep -q maxsize /etc/logrotate.d/apache2 || sed -i /weekly/amaxsize2M /etc/logrotate.d/apache2
   cat >> /etc/logrotate.d/ncp <<'EOF'
-/var/log/ncp.log
+/var/log/ncp/ncp.log
 {
         rotate 4
         size 500K
@@ -200,7 +207,7 @@ EOF
 
   # ONLY FOR IMAGE BUILDS
   if [[ -f /.ncp-image ]]; then
-    rm -rf /var/log/ncp.log
+    rm -rf "$LOGFILE"
 
     ## NEXTCLOUDPI MOTD 
     rm -rf /etc/update-motd.d
diff --git a/update.sh b/update.sh
index 761c4c3ac..def75198e 100755
--- a/update.sh
+++ b/update.sh
@@ -11,6 +11,7 @@
 set -e
 
 CONFDIR=/usr/local/etc/ncp-config.d/
+LOGFILE=/var/log/ncp/ncp.log
 
 # don't make sense in a docker container
 EXCL_DOCKER="
@@ -47,8 +48,26 @@ pgrep apt &>/dev/null && { echo "apt is currently running. Try again later";  ex
 type jq &>/dev/null || {
   apt-get update
   apt-get install -y --no-install-recommends jq
+
+}
+
+which tmux || {
+  apt install tmux locale
+}
+
+# Install UTF-8 locale required by tmux
+grep -v '#' /etc/locale.gen | grep -ie "en_US.UTF-8[[:blank:]]*UTF-8" &> /dev/null || {
+  echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen
+  locale-gen
 }
 
+# Migrate to new log location
+[[ -d /var/log/ncp ]] || {
+  mkdir -p "$(dirname "$LOGFILE")"
+  [[ -f /var/log/ncp.log ]] && mv /var/log/ncp.log "$LOGFILE"
+}
+
+
 # migrate to the new cfg format
 [[ -f "$CONFDIR"/dnsmasq.sh ]] && {
 
@@ -98,8 +117,9 @@ type jq &>/dev/null || {
 
   cat > /home/www/ncp-launcher.sh <<'EOF'
 #!/bin/bash
+
 source /usr/local/etc/library.sh
-run_app $1
+run_app "$1"
 EOF
   chmod 700 /home/www/ncp-launcher.sh
 }