Option A
Learn a language for free.
Duolingo is the world's most popular language-learning app, with gamified lessons in 40+ languages and 500M+ learners.
- Founder
- Luis von Ahn
- Founded
- 2011
- Team
- 500+
- Listing
- Free (nofollow)
- Listed
- May 2026
Option B
TestingJavaScript.com
Education
Learn the smart, efficient way to test any JavaScript application.
Kent C. Dodds' flagship paid testing course — an indie info-product generating significant revenue for a solo educator.
- Founder
- Kent C. Dodds
- Founded
- 2018
- Team
- 1-10
- Listing
- Free (nofollow)
- Listed
- May 2026