Learn Russian on Rosetta Stone
Rosetta Stone is a language-learning app that started in the 90s for auditory learners.
Price: Free
Devices: Android, Apple Watch, iPad, iPhone, and Web
Russian has so many unique concepts like успеть (to have enough time to do something; to do something (emphasizing that one had enough time to do it)), Да нет, наверное ( literally "yes, no, perhaps", means "no"), or Word Request (the word that describes the wildness of expansive wilderness).
You can learn Russian online on Mondly, Babbel, Memrise, Busuu, Drops, Pimsleur, Rosetta Stone, LinguaLift, Triplingo, or Lingopie.