This is more a note to myself than a full on tutorial.
Some of the Ionic apps I create need to create add something to local storage during startup of my app. The way I’ve been doing this recently is to run a service in the Run function of my app. Something like this:
I’ve used this a couple of times to load something in local storage, usually app settings. Then in my service (MyService.js) I can check what is stored in my settings, and if there is nothing there I can load them in via the same service.