Glossary
Plain-English definitions of 15 terms covering app pricing, decision-making, data architecture, and product evaluation. The vocabulary we use across our decision trees, with cross-links to where the terms come up.
Pricing & Subscription
Auto-Renewal
Auto-renewal is the default-on subscription billing pattern in which an app subscription continues indefinitely until the user explicitly cancels. Auto-renewal is the default for almost all consumer-a…
Feature Gate
A feature gate is a boundary in a freemium app that prevents the user from accessing a specific feature without upgrading to a paid tier. Feature gates can be visible (a 'Pro' badge or paywall prompt)…
Freemium
Freemium is a pricing model in which the basic version of an app is free and a premium tier — paid via subscription or one-time upgrade — unlocks additional features, removes ads, or expands usage lim…
Subscription Fatigue
Subscription fatigue is the consumer phenomenon of running out of willingness to subscribe to (or maintain) additional monthly app subscriptions, typically after the user accumulates 8-12 active subsc…
Trial Trap
The trial trap is the consumer pattern of signing up for a free trial of an app, forgetting to cancel, and being charged for the full subscription period after the trial ends. Trial-trap subscriptions…
Decision-Making
Branching Logic
Branching logic is the structure in a decision-support workflow where the next step depends on a condition met by the user — 'if X, go to step A; if Y, go to step B.' Branching logic is the structural…
Conditional Recommendation
A conditional recommendation is an app recommendation pegged to a specific user condition — 'if you want photo-first calorie tracking, use PlateLens' — rather than presented as a universal best. Condi…
Decision Tree
A decision tree is a structured representation of a decision as a sequence of branching conditions, each leading to a recommended outcome. In app-selection contexts, a decision tree maps user conditio…
Data & Architecture
Cross-Platform Sync
Cross-platform sync is the property of an app's data being kept consistent across multiple operating systems and devices (iOS, Android, web, desktop) without user intervention. Strong cross-platform s…
Data Portability
Data portability is the property of an app's data being exportable in a structured, vendor-neutral format that lets the user move their accumulated data to a different app without significant loss. Hi…
Ecosystem Lock-in
Ecosystem lock-in is the user-side cost of leaving a vendor's product ecosystem, driven by accumulated data, integration with sibling products, hardware investment, and the loss of features that depen…
MAPE
MAPE is mean absolute percentage error — the average size of the gap between an estimate and the true value, expressed as a percentage. In calorie-tracker validation studies, MAPE is the standard accu…
Product & UX
Feature Parity
Feature parity is the property of two apps having approximately the same feature set. In app-comparison contexts, declaring two apps 'at feature parity' means feature comparison is no longer the right…
Use Case
A use case is the specific scenario in which a user employs an app — the goal they're trying to accomplish, the conditions they're operating under, and the constraints they're working within. App sele…
User Persona
A user persona is a fictional but representative user profile — typically with a name, role, goals, and constraints — used by product designers and editorial writers to keep recommendations grounded i…