Shipmunks

Play famous chess games from their critical position against a friend, a rated opponent or Stockfish in your browser. 50+ legends, 3,600+ openings, divergence report. Free, open source (MIT).

Learn Vietnamese online with vetted native tutors — personalized 1-on-1 lessons from $10, a free 30-minute intro, and flexible subscriptions.

PrivateTechShares combines free discount-based equity estimators, an ESOP exercise-cost calculator and sourced country tax guides with paid US/EU secondary-sale toolkits for founders and leavers.

CertWorthIt cross-references 362,748 Adzuna job ads across 10 countries with AI analysis to show how often employers actually name PMP, CCNA, CompTIA, OSCP and AWS credentials.

Interview Practice lets you rehearse behavioral interview answers out loud on a timer — then an AI mock built from your resume and the job description scores each answer and shows what a stronger one looks like.

Real Excel exercises, challenges and tests with solutions. Every exercise pack covers multiple skill levels, from complete beginners to experienced users that want to push to their limits.