Share button language



I’m currently developing application for iOS that uses TWTRTimelineViewController provided by TwitterKit. Tweets have enabled action buttons (like and share). When I use share button and select Mail application then inside mail I can see following text:

Check out @…'s Tweet: https://…

Wysłane z iPhone’a

Application and iPhone, and tweet, and everything is set for Polish language, but shared text is in English. This doesn’t occur for every device (some have proper Polish text). So here’s my question: How do I set language so shared content is proper for user?