Thanks to our new "mobile app" promotion setting, you can configure the copy that should be used for promoting the mobile app to your members. This copy will be used in the footer of each message if you use our latest default mail template.
For this feature to work in your custom email template you need to add following block of code to your mail template.
Members that are using the web version of your community will also get a message that suggests installing the native app instead, because it will give them an improved user experience.