Transferring apps from old phone?

A German tutorial (could be translated via webservices easily) is here:

Not especially for /e/, but the basics seem compatible.

But I’m not used to “only” backing one application up with it.
For such a task I partly use the adb pull command.

There’s some information in this regarding SeedVault usage:

But regarding a tutorial for copy & paste I’ve not found anything specifically as well.