Rheo Code Journey

There is no shortage of apps that teach you to write code. But reading someone else's code and working out what it actually does? That is most of the job, and almost nobody practises it on purpose. Rheo drills exactly that. Every question puts a small piece of code in front of you and asks what it prints. You learn to trace it line by line, to spot the bug by eye, and to answer "what is happening here?" without guessing. HOW IT WORKS • Read the code, predict the output — the real output runs after you answer • Bug hunt: find the line that breaks it • Fill the missing piece, put scrambled lines back in order • When you get it wrong, an explanation that says why 10 CHAPTERS, 40+ LESSONS A path from variables to graph algorithms: conditionals, loops, functions, data structures, recursion, dynamic programming. Each chapter builds on the last. THREE LANGUAGES Python, JavaScript and Java, tracked separately so you can see where you stand in each. BUILT FOR THE HABIT • A daily streak, and a shield that protects it • XP, levels, badges and a daily goal • Leagues and timed duels • Daily quests and reward chests NO INTERNET NEEDED Everything ships inside the app. It works on the train, on a plane, off grid. NO ACCOUNT No signup, no login, no email. Open it and start. Your progress stays on your device. Reading code matters as much as writing it.