Creates a field with a serial number, so you can have the equivalent of a MySQL AUTO_INCREMENT field for a content type (if nodes are deleted the old serial number is not reused).
Although this only has a dev branch which hasn't had updates since April 2016, it does work in D8.
There's no direct migration path previous versions, but people have written their own migrations.
Check issue queue for patches - including:
- Support migrating existing values
- Removing deprecated entitymanager
- Serial module field tables not created during config synchronization
- Type not found for custom Entity