Learn Polish on Awabe
Awabe is a flashcard language learning app on Android. It focuses on vocabulary, offering as much as 4,000 words for each language.
Price: Free
Devices: Android, iPad, and iPhone
Polish has so many unique concepts like Kopanina ( an unattractive, low-level football match), rozkmina (youth slang for a complex plan made with a deep understanding of something), or Przymykać (to close something incompletely, leaving a gap).
You can learn Polish online on Mondly, Duolingo, Babbel, Memrise, Drops, Pimsleur, Rosetta Stone, Falou, Preply, or Cudoo.