Debugging: Inside the Machine
AP CSP & CSA debug practice
Free · Designed for iPad. Not verified for macOS.
Platformer + code-review game for AP CSP and AP CSA. Find the bug, fix the glitch, escape the firewall — fully offline, no account needed.
Debugging: Inside the Machine is a free debugging-practice arcade
platformer for students preparing for AP Computer Science Principles
or AP Computer Science A. You're inside a corrupted machine — find the
USB Key, fix the glitches, and escape the firewall before the system
collapses.
CSP and CSA modes ship in the same app. Tap once to switch.
— EASY · MED · HARD —
Each difficulty is a different level, with its own glitch tilemap and
its own question bank. CSP topics: Selection, Iteration, Functions &
Lists. CSA topics: Variables · Strings, Iteration · Loops, Arrays ·
Recursion. Two bonus levels (K-Pop Demon Hunters, Minecraft) unlock
when you've cleared all three difficulties.
— CODE LENS —
Glitches scatter across each level as collectible bugs. When you're in
range, the CODE LENS button pulses on screen. Tap it and a real
multiple-choice debugging question appears: read the broken code, pick
the actual bug from four explanations, and the glitch repairs.
Wrong answer? Stability drops 10 percent. Right answer? Stability
recovers 5 percent and the level inches closer to stable.
— Real questions, not filler —
Every question is hand-written and scoped to AP exam topics. No
random AI hallucinations, no off-curriculum trivia. The pseudocode
reference card (CSP) and Java Quick Reference (CSA) are one tap away
during any question.
— Built for phones and tablets —
Touch controls only. Bottom-left D-pad to move, big JUMP button on the
right, hold for higher jump. Question screens use full-size answer
buttons. Designed for landscape iPhone and iPad.
— Offline, no account, no tracking —
Everything ships in the app. The game makes zero network calls,
collects zero analytics, and requires no sign-in.
— More from CS++ —
A "More from CS++" button connects you to the rest of the CS++ family:
the AP CSP and AP CSA full-curriculum apps, the CS++ Java IDE for
on-device Java practice, and the free csplusplus.com web resources
(curriculum, vocab trainer, practice exams).
For: AP CSP and AP CSA students, CS teachers building exam prep
sessions, anyone who likes finding bugs.
What's new in 1.0.7
• Answer choices now use A, B, C, D — consistent with the AP exam.
• Question-bank cleanup: clearer wording, removed cases with more than one defensible answer, and repaired a Java snippet that didn't compile.
• Home-screen layout fix: the CSP/CSA mode toggle now stays on one line on smaller iPhones and no longer overlaps the Start button.
The developer, Kevin Hare, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Kevin Hare
- Size
- 6.8 MB
- Category
- Education
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPad
Requires iPadOS 15.0 or later. - iPod touch
Requires iOS 15.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Yellow Dart Publishing