Tally: A Privacy-First Subscription Awareness Application for Young Adults Aligned with the Sustainable Development Goals
Pelumi B. Oloyede
School of Science and Technology, Centro Escolar University, Manila, Philippines.
Joey O. Chua
School of Science and Technology, Centro Escolar University, Manila, Philippines.
Czarina Mitz N. Natino *
School of Science and Technology, Centro Escolar University, Manila, Philippines.
Eliza B. Ayo
School of Science and Technology, Centro Escolar University, Manila, Philippines.
*Author to whom correspondence should be addressed.
Abstract
Background: Recurring subscriptions have become a routine part of consumer spending, yet consumers consistently underestimate what they pay. In a survey of 2,500 U.S. consumers, 89% underestimated their monthly subscription spending, and an international review of 642 subscription websites and apps found that about 76% used at least one dark pattern. Automated tracking can require financial-account linking, whereas manual-entry tools offer an alternative for privacy-conscious users.
Study Design: This study used a design-and-development (design science research) approach.
Methodology: Tally is a privacy-first subscription awareness application. Design requirements were derived from literature on subscription fatigue, dark patterns, personal finance applications, financial privacy, behavioural nudges, and young adults’ financial behaviour, and from a focused, non-systematic comparison of four existing applications. A primary user persona guided AI-assisted interface prototyping in Google Stitch, and the application was implemented with offline-first local caching and optional Firebase Firestore synchronization. The artefact was examined through designer-led requirements traceability, four usability heuristics, calculated WCAG 2.1 colour contrasts, a design-level privacy assessment, and conceptual SDG mapping; no user testing or independent software security testing was performed.
Results: Tally presents a “True Monthly Total” with its annual equivalent, supports manual entry without bank credentials, and provides configurable pre-renewal reminders, billing-cycle-specific payment history, category reports, cancellation archiving with an illustrative annualised estimate of avoided charges, multi-profile workspaces, and PIN/biometric protection. Each persona pain point and design requirement was mapped to at least one prototype feature. The contrast check found two colour tokens below the WCAG 2.1 AA threshold for normal text, and the privacy review identified residual risks related to cloud synchronization, free-text fields, and receipt images. The conceptual SDG mapping is closest to Target 12.8, with more remote associations to Targets 8.10 and 16.10.
Conclusion: The Tally prototype integrates spending summaries, configurable renewal prompts, and a no-bank-linking design in a subscription-specific interface. Its intended effects on awareness, spending, and SDG-related outcomes have not yet been measured and must be established through empirical user testing.
Keywords: Subscription economy, subscription fatigue, privacy-first design, personal finance management, behavioral nudges, Sustainable Development Goals, young adults