use at your own risk and reponsibility.

A first try at customizing menus in maemo-leste

install:

download
leste-menu_noicon.tar.gz

extract to leste root

cd /
tar xvvf leste-menu_noicon.tar.gz

# copy icons (for example from maemo) to leste
scp -r /opt/usr/share/icons/hicolor/64x64/hildon/app_install* root@$maemo-leste-ip:/usr/share/icons/hicolor/64x64/hildon/
scp -r /opt/usr/share/icons/hicolor/64x64/apps/app_install* root@$maemo-leste-ip:/usr/share/icons/hicolor/64x64/apps/

# on leste
update-icon-caches /usr/share/icons/*

done.

Result should look very similar to http://maemo.hinoarashi.de/catorise/...526-190524.png from https://talk.maemo.org/showthread.php?t=73443

how it is done and some insights:

I just copied my maemo configuration generated by catorise over to leste.

Involving
/opt/catorise and /etc/xdg/menus/hildon.menu
/etc/xdg/menus/hildon.menu is a xml file, which uses /opt/catorise/share/*.directory as menus

At this time i have the usual catorise submenus, but right icons doesnt show up and the names are
ai_category_?

root@devuan:~# cat /opt/catorise/share/system.directory
[Desktop Entry]
Type=Directory
Name=ai_category_system
Icon=app_install_system
X-Text-Domain=hildon-application-manager

ai_category seems to be a naming convention from catorise.
So icons arent found and Name is taken.

Lets look at the user_guide

cat /usr/share/applications/hildon/user-guide.desktop
[Desktop Entry]
Encoding=UTF-8
Version=1.0
Name=tana_ap_user_guide
Comment=Show the user guide in a new window
Exec=dbus-send --print-reply --dest=com.nokia.osso_browser /com/nokia/osso_browser/request com.nokia.osso_browser.open_new_window string:http://maemo.nokia.com/n900/userguides/
Icon=tasklaunch_user_guide
Terminal=false
Type=Application
Categories=System
X-HildonDesk-ShowInToolbar=true
X-Osso-Type=application/x-executable

lets modify /opt/catorise/share/system.directory
root@devuan:~# cat /opt/catorise/share/system.directory
[Desktop Entry]
Type=Directory
Name=ai_category_system
#Icon=app_install_system
Icon=tasklaunch_user_guide
X-Text-Domain=hildon-application-manager

and we get a nice white on blue question mark.

find / | grep tasklaunch_user_guide
/usr/share/icons/hicolor/64x64/hildon/tasklaunch_user_guide.png

on maemo
find / | grep app_install_system
/opt/usr/share/icons/hicolor/64x64/apps/app_install_system.png
/opt/usr/share/icons/hicolor/64x64/hildon/app_install_system.png


so to be save i copy both, (they seem to be the same)
scp -r /opt/usr/share/icons/hicolor/64x64/hildon/app_install* root@$maemo-leste-ip:/usr/share/icons/hicolor/64x64/hildon/
scp -r /opt/usr/share/icons/hicolor/64x64/apps/app_install* root@$maemo-leste-ip:/usr/share/icons/hicolor/64x64/apps/

no, still just tasklaunch_user_guide icon is working.

ok, i guess we need to update some icon cache

after
update-icon-caches /usr/share/icons/*
(and a reboot ?)
we have working icons (great) and .. names, ahm (thats different on maemo), great (if the names werent all ai_category_? like on maemo).

[fix using emacs on path /opt/catorise/share
dired-do-query-replace-regexp Name=ai_category_ Name=
doesnt work ???]

but sed did
cd /opt/catorise/share
find ./ -type f -exec sed -i -e 's/Name=ai_category_/Name=/g' {} \;

resulting in more meaningful names

lets try to install a debian packet and see if it shows up, lets try something small and useful: mc

apt-get install mc

and it didnt show up (there is a known fix https://github.com/maemo-leste/bugtracker/issues/82)

cp /usr/share/applications/mc.desktop /usr/share/applications/hildon/mc.desktop

update-icon-caches /usr/share/icons/*

Icon and name should show up, but it doesnot launch. (https://github.com/maemo-leste/bugtracker/issues/165)
Lets look why.

# devuan
cat /usr/share/applications/mc.desktop
[Desktop Entry]
Name=Midnight Commander
Name[af]=Middernag Kommandeur
Name[eo]=Meznokta komandanto
Name[fa]=فرمان*دار نیمه شب
Name[ko]=미드나잇 커멘더
Name[lv]=Pusnakts Komandieris
Name[nso]=Molaedi wa Bosegogare
Name[th]=มิดไนท์คอมมานเดอร์
Name[ve]=Muhulwane wa vhukati ha vhusiku
Name[xh]=Umyaleli Waphakathi kobusuku
Name[zu]=Umyaleli waphakathi nobusuku
Comment=File manager
Comment[pl]=Menedżer plików
Exec=mc
Icon=MidnightCommander
Terminal=true
Type=Application
Categories=ConsoleOnly;Utility;FileManager;System; FileTools;
Keywords=file manager;console;

# on Maemo
cat /usr/share/applications/hildon/mc.desktop
[Desktop Entry]
Encoding=UTF-8
Version=1.0
Type=Application
Name=Midnight Commander
Comment=Console-based file manager and visual shell
Exec=osso-xterm -e mc
Icon=mc
# Terminal=true does not work in Maemo
X-Window-Icon=mc
X-Window-Icon-Dimmed=mc
X-HildonDesk-ShowInToolbar=true
X-Osso-Type=application/x-executable

Found "Terminal=true does not work in Maemo"
fixing to

root@devuan:~# cat /usr/share/applications/hildon/mc.desktop
[Desktop Entry]
Name=Midnight Commander
Name[af]=Middernag Kommandeur
Name[eo]=Meznokta komandanto
Name[fa]=فرمان*دار نیمه شب
Name[ko]=미드나잇 커멘더
Name[lv]=Pusnakts Komandieris
Name[nso]=Molaedi wa Bosegogare
Name[th]=มิดไนท์คอมมานเดอร์
Name[ve]=Muhulwane wa vhukati ha vhusiku
Name[xh]=Umyaleli Waphakathi kobusuku
Name[zu]=Umyaleli waphakathi nobusuku
Comment=File manager
Comment[pl]=Menedżer plików
Exec=osso-xterm -e mc
Icon=MidnightCommander
#Terminal=true
Type=Application
Categories=ConsoleOnly;Utility;FileManager;System; FileTools;
Keywords=file manager;console;

starts mc in osso-xterm


to put it in a category edit /etc/xdg/menus/hildon.menu

for example in utilities:
...
<Menu>
<Name>utilities</Name>
<Directory>utilities.directory</Directory>
<Include>
<Filename>emacs24.desktop</Filename>
<Filename>mc.desktop</Filename>
<Filename>osso-xterm.desktop</Filename>
</Include>
<Layout>
<Filename>mc.desktop</Filename>
<Filename>osso-xterm.desktop</Filename>
<Filename>emacs24.desktop</Filename>
</Layout>
</Menu>
<Menu>
<Name>all</Name>
<Directory>all.directory</Directory>
<Include>
<All/>
</Include>
<Layout>
<Filename>osso-xterm.desktop</Filename>
<Filename>emacs24.desktop</Filename>
<Filename>mc.desktop</Filename>
<Merge type="all"/>
</Layout>
<Exclude>
<Filename>catorise-browser.desktop</Filename>
<Filename>catorise-calendar.desktop</Filename>
<Filename>catorise-image-viewer.desktop</Filename>
<Filename>catorise-modest.desktop</Filename>
<Filename>catorise-osso-addressbook.desktop</Filename>
<Filename>catorise-rtcom-call-ui.desktop</Filename>
<Filename>catorise-rtcom-messaging-ui.desktop</Filename>

</Exclude>
</Menu>
...

I dont know if there is a way to not repeat the entry in Include and Layout. Layout defines the actual gui position.
So in "utilities" mc goes first, in "all" osso-xterm.


Remarks
You cant currently use /debian/.desktop files in hildon directly cause terminal=true is not supported.
So currently seperation of /debian/.desktop and /hildon/.desktop files make sense,
you have to "import" them and cant just add the /usr/share/applications directory.
This alignes with the different ui interfaces of hildon apps and debian apps.
(and their problems right click, drag and drop, hover, keyboard shortcuts collisions)

osso-xterm -e should be something like debian-terminal-app i just used osso-xterm -e cause i didnt know better.
(Is something like debian-gui-app needed too?)

You currently have to modify (maemo-hildon) catorise for rebased hildon to fix "Name"s.

Rant
To make a nice menu creation application for hildon (hildon-rebased and many other modern UX) you need to follow
the (free)Desktop(.org) Menu Specification (which uses xml in Menus and the "Desktop Entry Specification"
which includes a simpler own file format)
and finally find out about the current icon caching mechanism.

different formats, different tools, different bugs, more to learn, easier to automate.