When localizing iOS and macOS apps, Xcode requires the use of .strings files and additional .stringsdict files (see here) for encoding pluralization rules. I am looking for a way to combine both of these into a standard format like Gettext PO in order to import them into a translation management tool like Pootle.
.strings files can be converted to PO using prop2po from the Translate Toolkit (see here). However, I am unable to find anything for including .stringsdictfiles in the conversion.
It also seems that Xcode does not include the .stringsdict files when exporting localization files (see here).
Answering myself here. A direct conversion between .stringsdict and .po files is not possible because strings dicts support more than one pluralizable variable whereas PO files have only one single counter.