This has never been very successful for me. Available methods are
- For me its
Samsung Smartswitch, - There is
OnePlus Switch - Otherwise
Android Backup and Restore - Helium Backup
- Titanium Backup
You install them on both devices, some work with wifi, some with cable, others either way. The following is based on Samsung Smartswitch but I believe its the same with the OnePlus and Android toosl. I have not tried Helium or Titanium Backups.
- It copies all apps (that are free) and their data.
- It does not copy paid apps or their data or both. I can understand this, otherwise it could be used to make copies of them with payment record intact
- You have to re-register the paid-up apps again. Some recognise that they were paid for before, others do not.
- You have to re-register apps such as banking apps and authentication apps.
adb backupdoesn't work anymore on recent phone for non-outdated apps. This leaves you to backup/restore via cloud or direct USB connection between old & new phone. IMHO the best option is the USB cable.