I have developed an app that I want to publish in the Odoo App Store. The issue I am now facing is how to add an Icon for it that will be seen in the Apps tab once the app is installed.
You should have that icon file anywhere in the static directory of your app/module. Why static? Because it is easier to configure web caching (with apache or nginx) if every app/module has static files at the "same" directory.
You also have to tell your menu which icon file to use, like in the Accounting App.
<menuitem name="Invoicing"
id="menu_finance"
groups="account.group_account_readonly,account.group_account_invoice"
web_icon="account,static/description/icon.png"
sequence="55" />