UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.63 Safari/537.36

Steps to reproduce the problem:
1. Install a Chrome app such as "Google Play Music" or find an existing one in chrome://apps
2. Locate the corresponding .desktop file created in ~/.local/share/applications. For Google Play Music it is called ~.local/share/applications/chrome-fahmaaghhglfmonjliepjlchgpgfmobi-Default.desktop
3. Open the file in a text editor

What is the expected behavior?
The file should contain a Categories key so that it can be displayed in start menus. See for reference https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html section "Recognized desktop entry keys", table "2. Standard Keys".

The value should be "Network;Chrome Apps;". This is because they match the standard "Network" category (https://specifications.freedesktop.org/menu-spec/menu-spec-1.0.html) and also the more specific "Chrome Apps" category which exists thanks to the file ~.local/share/desktop-directories/chrome-apps.directory:

[Desktop Entry]
Version=1.0
Type=Directory
Name=Chrome Apps
Icon=google-chrome

So for example, for Google Play Music, the current file is:

#!/usr/bin/env xdg-open
[Desktop Entry]
Version=1.0
Terminal=false
Type=Application
Name=Google Play Music
Exec=/opt/google/chrome/google-chrome --profile-directory=Default --app-id=fahmaaghhglfmonjliepjlchgpgfmobi
Icon=chrome-fahmaaghhglfmonjliepjlchgpgfmobi-Default
StartupWMClass=crx_fahmaaghhglfmonjliepjlchgpgfmobi

To fix it I would append the following line:

Categories=Network;Chrome Apps;

What went wrong?
Currently there is no "Categories" key in the desktop files, so the shortcuts end up in the "Other" category in the start menu, unless the start menu hardcodes some regex to match the Exec value.

WebStore page: 

Did this work before? No 

Chrome version: 51.0.2704.63  Channel: stable
OS Version: 
Flash Version: Shockwave Flash 21.0 r0