Learn on Brainscape

Brainscape is a customizable flashcard language learning app where you can pick the language you want to learn and then create your own personalized learning path. It prides itself on being "the world's smartest flashcard app".
Price: $9.99/month
Methods: Flashcards
Devices: Android, iPhone
Total languages offered: 103
Other languages:

Learn on LuvLingua

LuvLingua is a language learning app that uses an interface that is more geared towards a younger audience. It's focused on vocabulary learning and listening skills. The basic app is free but the more advanced ones are paid.
Price: Free (with premium plan)
Methods: Games, Quizzes
Devices: Android, iPad, iPhone, Web
Total languages offered: 13
Other languages:

Learn on Rosetta Stone

Rosetta Stone is a language-learning app that started in the 90s for auditory learners.
Price: Free (with premium plan)
Methods: Online Courses
Devices: Android, Apple Watch, iPad, iPhone, Web
Total languages offered: 24
Other languages:

Learn on Ling

Ling's app has features that make learning fun and easy. Whether you're a beginner or an experienced speaker, Ling has something for everyone. You learn at your own pace with tons of lessons, vocabulary lists, and quizzes. You can even practice your conversation skills with their chatbot.
Price: Free (with premium plan)
Methods: Games, Quizzes
Devices: Android, iPad, iPhone, Web
Total languages offered: 61
Other languages:

Learn on Udemy

You can use Udemy to learn a new language. Courses such as "Learn Dutch Beginner" and "French Language Learning: Language and Culture for Absolute Beginners," will help kickstart you in those two languages.
Price: Free (with premium plan)
Methods: Tutors
Devices: Web
Total languages offered: 19
Other languages: