Causal Loop Diagram

"Causal Loop Diagram" is a fast, focused editor for sketching causal loop diagrams (CLDs) on iPhone — a foundational tool of systems thinking.

Place variables, draw arrows, set polarities (+/−), and the app automatically detects feedback loops and classifies the whole diagram against well-known systems-thinking archetypes.

— Features —

■ Simple drawing
• Tap empty area to add a node, then tap source → target to link
• Long-press an arrow to add a delay marker (||)
• Drag nodes freely; pinch to zoom; one-finger drag on empty area to pan

■ Automatic loop detection
• The moment a cycle closes, an R (reinforcing) or B (balancing) badge appears
• Each loop is numbered (R1, R2, B1, B2…) so overlapping loops stay distinguishable
• Tap a badge to highlight that loop's interior; other loops dim

■ Nine archetypes auto-classified
• Reinforcing loop / Balancing loop
• Limits to Growth
• Fixes that Fail
• Shifting the Burden
• Escalation
• Success to the Successful
• Tragedy of the Commons
• Growth and Underinvestment

■ Seven curated samples
Familiar themes — study, family, sibling rivalry — to learn each archetype by example:
• Study Habit (R)
• Calibrating to Target Score (B)
• Limits to Growth: Fatigue
• Shifting the Burden: Escapism
• Fixes that Fail: All-nighter
• Escalation: Sibling Rivalry
• Tragedy of the Commons: Parent's Attention

■ Privacy
• No network access at all
• No account, no sign-in
• No analytics or tracking SDKs
• Diagrams stored only in UserDefaults; uninstalling removes everything

■ Other
• Japanese / English UI, one-tap switch
• Save multiple diagrams locally with custom names
• iOS 16+ (iPhone 8 and later)

— Who is this for —

• Students of systems thinking and system dynamics
• Managers and designers who think in structures
• Anyone who wants to step back and see the loops in their own habits, relationships, or work
• Educators preparing diagram examples on the fly

Pairs naturally with Peter Senge's "The Fifth Discipline" and other systems-thinking textbooks — turn the loops in your head into something you can draw and touch in seconds.