Math Daily

Inspiration

Mental math is a skill you lose quietly. Phones do the arithmetic for us, and most practice apps feel like homework: a wall of problems and a score. We wanted something you'd actually open every day, closer to a language learning streak than a worksheet, and friendly enough for a kid but quick enough for an adult on a coffee break.

What it does

Math Daily is short, focused mental-math practice built around the Math Monsters, four original characters each shaped like its operator: Plumo (+), Mino (−), Tixi (×) and Divvy (÷).

• Pick who's practicing. Tap the monsters to choose any mix of operations, then practice at Easy, Medium or Hard.
• The monster is the operator. Problems read 7 [Tixi] 8, and the monster hops when you're right and droops when you're wrong. A number pad with Liquid Glass keys makes answering fast.
• Chain mode (Pro). Multi-step problems like 14 + 6 × 3 − 9, with order of operations whenever × or ÷ is involved.
• Stay consistent. Daily streaks, history with accuracy per operation, and a "Practice your mistakes" review list that brings missed problems back until you get them right (Pro).
• 26 achievements, including a few hidden ones, with a trophy case and confetti made of + − × ÷ in the monsters' colors.
• Game Center. Leaderboards for the fastest perfect 10 split by difficulty so rankings are fair, problems solved today, this week and over 30 days, and longest streak. Challenges let you race a friend, and Activities like "Tixi's Times Tables" launch straight into a preset session from the Games app.
• iPhone and iPad, with a side-by-side practice layout in iPad landscape, and iCloud sync of history.

How we built it

• UIKit, written in Swift 6 with strict concurrency. The monsters are drawn in code with Core Animation (shape layers, blinking, bobbing, hop and droop reactions), so they stay crisp at any size. A small Python script redraws the same designs as SVG for the website (whose monsters' eyes follow your cursor), the app icon, the achievement badges and the store artwork.
• RevenueCat powers all purchases. The Pro entitlement unlocks Chain mode, Hard, longer sessions and mistake practice. The paywall is a custom UIKit screen built from the current RevenueCat offering, so plans and prices come from the dashboard and never have to be hardcoded. It checks trial and intro-offer eligibility per plan and only advertises offers the user can actually redeem, with a timeline for "what happens when" and an optional reminder before a free trial ends.
• Game Center for achievements, 15 leaderboards in 3 sets, challenges and activities, plus iCloud key-value storage for sync.
• Automation: App Store Connect was driven almost entirely from the command line with asc: subscriptions and territory pricing, intro offers across 175 territories, Game Center items with artwork, screenshots and review submissions. A single release.sh bumps the build, runs the tests, captures screenshots on iPhone and iPad, uploads and attaches the build, deploys the site to Cloudflare and checks review readiness.

Challenges we ran into

• Game Center's undocumented limits. Recurring leaderboards only repeat by minutes, hours or days and cap a period at 30 days, so "monthly" became a 30-day window.
• Fair speed leaderboards. One "fastest perfect 10" board ranked Easy against Hard, so it's split per difficulty, with chains on their own board.
• Keeping achievements honest across devices. Unlocks are derived from recorded history instead of stored flags, so they survive iCloud merges and reinstalls and can't drift.

Accomplishments that we're proud of

A cast of characters that is the math, not decoration around it.

What we learned

Subscription UX is mostly about removing surprise. A low-commitment start, a clear timeline and a reminder build more trust than any badge. And for a daily habit app, sound, haptics and a character reacting to you matter as much as the core loop.

What's next for Math Daily

• An answer style option (type or pick), with smart wrong answers that diagnose mistakes
• More monsters and seasonal challenges, plus a kid-friendly mode

Built With

• core-data
• gamekit
• icloud
• revenuecat
• storekit
• swift
• uikit