Usually, no (but see also When do you need an Add-on ID?). Mandatory before Firefox 48 (desktop) and Firefox for Android.
A chave applications contém chaves que são especificas de uma application de um anfitrião em particular.
id is the extension ID. Optional from Firefox 48, mandatory before Firefox 48. See Extensions and the Add-on ID to see when you need to specify an add-on ID.
strict_min_version: minimum version of Gecko to support. Versions containing a "*" are not valid in this field. Defaults to "42a1".
strict_max_version: maximum version of Gecko to support. If the Firefox version on which the extension is being installed or run is above this version, then the extension will be disabled, or not permitted to be installed. Defaults to "*", which disables checking for a maximum version.
update_url is a link to an extension update manifest. Note that the link must begin with "https". This key is for managing extension updates yourself (i.e. not through AMO).
Consulte a lista das versões válidas de Gecko.
The latter format is easier to generate and manipulate. Be aware that using a real email address here may attract spam.
Boolean property which controls the placement of the browser action.
true is equivalent to setting browser_action.default_area to navbar.
false is equivalent to setting browser_action.default_area to menupanel.
Example with all possible keys. Note that most extensions will omit strict_max_version and update_url.