There’s no good reason to use localStorage for anything. Its weak persistence guarantees make it inappropriate for persisting things between app runs, and using it for in-app communication is slow and not type-safe.
I would suggest using Ionic Storage instead. As for your stale data problem, I use a structure like this.
IF you absolutely want to save the data using localstorage so some reason use the jwtwebtoken package.
This way the user will be able to see the data on localstorage but making changes to if will corrupt OR pollute the data to be used inside the app.
Also for the question as to “how to change the data in app after the user saves it”
you will need a localstorage.getItem instead of setItem
The reason as to why the name is not changing is because that data is not reactive in itself. depending of the framework you will need to “Watch” that data for a change and then fire a command to update it