Product Designer · Singularity Hub · 2023–2024
Singularity Words

Word Learning

1

Forgotten in a week

Students learn words, pass a test — and forget 80% within a week. Vocabulary stagnates. Teachers can't see which words are stuck.

Singularity Words fights the forgetting curve. The algorithm selects words, schedules reviews, adapts difficulty per student. Target metric: 1 word per minute retained in long-term memory.

2
platforms: Android + iOS
3,200+
words in the database
100K+
Google Play downloads
4.7
Google Play rating
2

The accordion — drill mechanic

Three iterations. First — a plain word list. Second — interactive flashcards. Third — an accordion: translation, examples, synonyms unfold progressively. Each iteration tested a hypothesis. List — is simple repetition enough? Cards — does interaction help? Accordion — does rich context improve retention? A/B tests confirmed: the accordion gives the best memorization.

A word is considered "drilled" when translated correctly in 60%+ of attempts. Three modes: reading, speaking aloud, typing.

Accordion mechanic — word cards expand with context and examples
Drilling v.3 Accordion: translation, examples, three training modes
iOS drilling — native controls, SF Symbols
iOS: native drilling with SF Symbols and system controls
Speaking — voice training mode: ASR, recording, re-recording
Speaking v.3: voice mode — speech recognition, re-recording, progressive hints
N-gram drilling — phrase and collocation training
N-gram drilling: phrase and collocation training, mechanic iterations
3

Spaced repetition

The algorithm detects when a word is about to be forgotten and brings it back. A word starts hidden: r_____y. Letters appear one by one if the student can't recall. After training — contextual results: "80% correct, better than 92% of students." Competitive element without pressure. Design decision: "Skip" renamed to "Continue" — makes the action clearer.

Spaced repetition — progressive letter hints and results
Spaced Repetition: hidden word → letter-by-letter hints → result with percentile
Spaced Repetition redesign (September 2024) — updated review interface
Spaced Repetition redesign (September 2024): updated visual review system
4

Statistics and levels

CEFR levels: A1 → A2 → B1 → B2 with numeric precision. Example: level A2.32, session access at B1.54+. Target: 2,000 words by exam session. Activity is color-coded: green (80–100%), yellow (60–79%), orange (40–59%), red (0–39%). Trends compare current week to previous. iOS widgets bring progress to the home screen.

iOS statistics — levels, weekly calendar, activity, leaderboard
iOS: CEFR levels, weekly calendar, word statistics, leaderboard
5

Android + iOS

One UX, two native implementations. Android — Material Design 3, XML palette, dark theme. iOS — SF Symbols, native controls, WidgetKit home screen widgets.

The feed went through three versions. v.1 — tabs (Words / Grammar / Profile). v.2 — light theme, training cards with time windows. v.3 — bottom nav removed, profile moved to top bar, Lottie confetti on completion. Each iteration tested with real students.

Feed evolution: v1 tabs, v2 light cards, v3 without bottom nav
Feed evolution: v1 tabs → v2 light cards with time windows → v3 profile in top bar, Lottie confetti
Card feed — light theme, Material Design 3
Android: Cards v.2 Light, unified feed with a daily session
iOS — WidgetKit widgets, activity, progress
iOS: WidgetKit widgets, activity tracking, word and grammar progress
Widget iterations: Statistics v1.2, Single Widget, Double Widget
iOS widget iterations: statistics v1.2 → single widget → double widget (words + grammar)
6

Launch

Three iterations of the Google Play listing. Key messages: "Progressive difficulty," "Spaced repetition," "Optimal workload." A CSI survey is embedded in the app: "How well does the app help you learn words?" Feedback flows directly into product decisions. 100K+ downloads. 4.7 rating.

Google Play listing — three iterations: v1, v2, v3
Google Play: listing evolution v1 → v2 → v3
CSI survey — in-app satisfaction questionnaire
CSI survey: in-app satisfaction questionnaire driving product decisions
7

My role

Product designer on a team of four. Vision — George Solovev. Product — Ksenia Golovina. Dev Lead — Ivan Pyatin.

  • UX research, prototypes, A/B tests
  • UI: Android (Material 3) + iOS (native controls, WidgetKit)
  • Core mechanics: accordion drill, spaced repetition, level system
  • Statistics: activity tracking, CEFR levels, iOS widgets
  • Marketing: 3 iterations of Google Play listing
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