How to put a (Start) Menu button on Fluxbox Toolbar

In your $HOME/.fluxbox/init file, look for the line that defines the tools on your toolbar, and add a "RootMenu" item where you want it to appear. Here's what mine looks like:

session.screen0.toolbar.tools:  RootMenu, iconbar, systemtray, clock

Edit: Solution at https://sourceforge.net/tracker/index.php?func=detail&aid=3551120&group_id=35398&atid=413963#

there's the Fluxbox Tray Menu http://sourceforge.net/projects/ftmenu/ but unfortunately it has to be in the system tray...

right now I'm using "Mod4 Mouse3 :RootMenu" and "OnToolbar Mouse2 :RootMenu" in my keys file

At this time 2018 the only way to install ftmenu in Ubuntu 18.04 are installing this dependences:

sudo apt-get install git libgtk2.0-dev

next put one by one in command line:

git clone https://github.com/taq/ftmenu
cd ftmenu
./configure
make
sudo su
make install

Then run in terminal with:

ftmenu

you obtain this:

But the only problem is that some icons are big

Well, to obtain this menu firt is neccesary to install xdgmenumaker with this:

sudo apt-get install git txt2tags
git clone https://github.com/gapan/xdgmenumaker
cd xdgmenumaker
make
sudo su
make install

Then you need to follow this steps:

1.- Edit "menu" file under .fluxbox hidden folder:

gedit ~/.fluxbox/menu

2.- Delete manually all text and copy and paste this:

[begin] (fluxbox)
[include] (~/.fluxbox/xdg_menu)
   [config] (Configuration)
   [workspaces] (Workspaces)
   [reconfig] (Reconfigure)
   [restart] (Restart)
   [exec] (Update Fluxbox Menu) {xdgmenumaker -i -s16 -f fluxbox > ~/.fluxbox/xdg_menu}
   [exit] (Exit)
[end]

save and close

3.- Restart fluxbox or close session.

4.- Activate menu, right clic in desktop and clic in "Update Fluxbox Menu"

Here an snapshot of all menu apps when you give right clic:

God Bless