Automatic updates from ThemeForest.net
Using a Personal Token a list of purchases made with the corresponding Envato account are compared to the actively installed themes. If a theme needs an update it will appear alongside other themes in the standard WordPress update flow.
This "plugin" does not implement itself by default. The /updater directory
should be place instead the theme, and a bootstrap file should be created in
order to set everything up.
You can see an example in the /examples directory.
API code based on wp-envato-market