Online Coding Challenges
HackerRank – Improve your coding skills and expand your technology knowledge.
CodinGame – Play games, solve puzzles, all while coding in your favourite language.
Development
gitignore.io – Generate .gitignore files.
Writing
Hemmingway – Great online editor that’ll make your writing so much better.
Grammarly – Improve your grammar on any web page which requires user input.