Bubbles
Zearn's first iOS app — a game where kids practice multiplication by popping number bubbles on a spaced-repetition loop.
Target Product: 42 · Pop the Factor Pair!
- Floating bubbles: [ 6 ] + [ 7 ] → POP! = 42 (+10 pts)
- Distractor bubbles: [ 8 ] [ 5 ] drift apart with gentle physics bounce
- Zero countdown panic timer — designed to feel like play, not a pop quiz
Student Mastery Matrix · Fact 7×8 Flagged
- Mastered (<1.5s recall): 3×4, 5×6, 6×6, 2×9 → interval widened to 14m
- Learning (hesitation 3.8s): 6×7, 7×8 → re-seeded in next 3 bubble waves
- Scaffold mode: splits 7×8 into (5×8=40) + (2×8=16) visual array hint
15-Minute Math Station · 38 Facts Practiced
- Accuracy: 91% across 38 bubble pops · 0 remedial worksheet drills
- Newly automatic this session: 6×7=42, 8×4=32, 9×3=27, 7×6=42
- Next session warm-up queued: 7×8 and 8×9 factor families
As Zearn’s first PM, I owned Bubbles — our first iOS app — alongside Number Gym, two of the company’s four early product lines. Each round adapted to where the student was: facts a kid missed came back on a spaced-repetition schedule, while mastered tables stepped out of the way so practice felt like a game rather than a drill. We tested the prototype directly with elementary classrooms in NYC public schools to tune the pacing and difficulty curve.