How to install changes of custom app from github

I have set up erpnext
Now and pushed my custom app code to github and pulled into it a separate machine.
Now first time I was able to get and the install app.
How do I pull and install the changes from github custom app code repo?

bench get-app repo_address
bench --site site_name install-app custom_app_name

bench update should pull latest changes from each app by pulling latest code from those apps.

Only bench update or any other commands like bench migrate or something?