Mizzle

Overview

Mizzle is a weather app for iOS that turns mundane weather checking into a delightful experience. Built with SwiftUI, it features playful animations, warm design, and personality-filled forecasts that make even rainy days feel a bit brighter. Created as a teenager learning iOS development, Mizzle became a beloved app for thousands of users who wanted their weather with a side of joy.

The Problem

Weather apps are notoriously cold and clinical. Most follow the same formula:

  • Sterile white or dark backgrounds
  • Walls of numbers and data
  • Corporate, joyless language (“Precipitation probability: 87%”)
  • Generic icons that all look the same
  • Information overload with no personality

I grew up in the Netherlands, where rain is constant. Checking the weather was part of daily life, but every app made it feel like a chore. I wanted something that would make me smile, even when telling me it’s going to rain (again).

As a teenage developer learning Swift, I saw an opportunity to build something different: weather that feels like a friend texting you, not a robot reporting data.

The Vision

What if checking the weather could be:

  • Warm and friendly instead of cold and clinical
  • Playful without sacrificing accuracy
  • Beautiful with delightful animations
  • Personal with natural language and personality
  • Simple showing what matters, hiding the rest

Design Philosophy

Visual Language

  • Warm color palette: Soft oranges, gentle purples, muted blues
  • Smooth animations: Every interaction feels fluid and intentional
  • Generous spacing: Room to breathe, nothing feels cramped
  • Custom illustrations: Hand-crafted weather icons with character
  • Dynamic backgrounds: Colors and gradients that match the weather

Tone of Voice

Instead of “Precipitation: 80%”, Mizzle says things like:

  • “Grab a brolly, it’s gonna be wet out there”
  • “Perfect hoodie weather today”
  • “Sunglasses required ☀️”
  • “It’s a duvet day kind of forecast”

Weather updates feel like texts from a friend who cares whether you’re comfortable.

Features

Current Weather

  • Large, readable temperature display
  • Natural language summary (“Cloudy with a chance of smiles”)
  • “Feels like” temperature with context
  • Animated weather conditions
  • Wind and humidity when relevant

Hourly Forecast

  • Horizontal scroll through next 24 hours
  • Simplified to what matters: temp, conditions, rain chance
  • Visual precipitation graph
  • Smooth transitions between hours

Daily Forecast

  • 7-day outlook at a glance
  • High/low temps with weather icons
  • Expandable for more details
  • Rain probability indicators

Delightful Details

  • Rain radar: Animated precipitation map showing rain movement
  • Notifications: Optional morning/evening forecast alerts
  • Widgets: Home screen widgets in multiple sizes
  • Apple Watch: Glanceable complications and dedicated app
  • Dark mode: Automatically adjusts to system preference
  • Location aware: Auto-detects or saves favorite locations

Technical Implementation

SwiftUI Architecture

Built entirely in SwiftUI (no UIKit), making Mizzle an early adopter showcase:

// Core architecture
- App entry point with @main
- MVVM pattern with ObservableObject view models
- Combine for reactive data flow
- Async/await for API calls (modern concurrency)

Key Technical Components

1. Weather API Integration

  • Primary: Apple WeatherKit for native integration
  • Fallback: OpenWeatherMap API
  • Custom data layer abstraction for easy provider switching
  • Efficient caching to minimize API calls
  • Background refresh for up-to-date data

2. Animation System

  • Custom particle systems for rain, snow, clouds
  • Lottie integration for complex animated icons
  • Spring physics for interaction animations
  • 60fps performance maintained throughout

3. Location Services

  • CoreLocation for device positioning
  • Geocoding for location search
  • Multiple saved locations support
  • Privacy-first: location data never leaves device

4. Widget Development

  • WidgetKit implementation
  • Timeline provider for updates
  • Multiple widget families (small, medium, large)
  • Dynamic coloring based on weather

5. Data Persistence

  • UserDefaults for preferences
  • Custom caching layer for API responses
  • CoreData for saved locations (considered, but went simpler)

Technical Challenges

Challenge 1: Animation Performance Early versions suffered from frame drops during weather transitions. Solved by:

  • Optimizing view hierarchies
  • Using .drawingGroup() for heavy animations
  • Preloading animation assets
  • Implementing smart animation disabling on older devices

Challenge 2: SwiftUI Limitations As an early SwiftUI adopter, I hit framework limitations:

  • Had to drop down to UIKit for certain gestures
  • Worked around buggy List behaviors
  • Created custom components when native ones were unstable
  • Many bugs were fixed in iOS updates over time

Challenge 3: Accurate Weather Personality Matching tone to weather required nuance:

  • Built a context-aware text generator
  • Considered temperature, conditions, time of day, season
  • Tested hundreds of phrases with friends
  • Created fallback logic to avoid repetition

Development Journey

The Beginning (Age 16)

  • Learned Swift through Apple’s official tutorials
  • Started with basic “Hello World” apps
  • Gradually tackled more complex UI challenges
  • Mizzle began as a weekend project

First Version (3 months)

  • Basic weather display with static design
  • Simple API integration
  • Published to App Store as free app
  • Got first 100 downloads from friends and family

Iteration Cycle (1 year)

  • Added animations based on user feedback
  • Implemented widgets with iOS 14
  • Refined personality and copy
  • Grew to 1,000+ users organically
  • Featured in Dutch iOS dev community

Polish & Growth (6 months)

  • Complete redesign with refined color palette
  • Apple Watch app
  • Advanced animations and interactions
  • Press coverage in iOS dev blogs
  • Reached 5,000+ downloads

Results & Reception

Downloads & Usage

  • 10,000+ total downloads (entirely organic, no marketing spend)
  • 4.7/5.0 App Store rating (250+ reviews)
  • 2,500 active monthly users
  • 60% daily active users (exceptionally high for weather app)
  • Featured in “New Apps We Love” in Netherlands App Store

User Feedback

Reviews consistently mention:

  • “Finally a weather app with personality!”
  • “The animations make my day”
  • “It’s like weather updates from a friend”
  • “Most beautiful weather app I’ve used”
  • “Makes checking rain fun somehow”

Recognition

  • Featured in 3 iOS development blogs
  • Showcased in SwiftUI tutorial series (2 YouTube channels)
  • Used as case study in local programming meetup
  • Mentioned in Dutch tech podcast

Personal Achievement

Built and shipped as a teenager with:

  • Zero budget (used free API tier)
  • No formal computer science education yet
  • Self-taught through documentation and experimentation
  • Entirely solo project (design, development, marketing)

Learnings

Technical Skills Gained

  • SwiftUI mastery: Became deeply familiar with the framework
  • API integration: Learned REST APIs, JSON parsing, error handling
  • Async programming: Mastered Combine and async/await patterns
  • App Store process: Submission, review, updates, metadata
  • Performance optimization: Profiling, debugging, testing on real devices
  • Widget development: WidgetKit and extension architecture

Product Lessons

  • Personality matters: Users connect with apps that have character
  • Simplicity wins: Showing less data more beautifully beats data dumps
  • Animations delight: Motion brings interfaces to life
  • Feedback loops: User reviews guided every major improvement
  • Niche is okay: Better to be loved by few than liked by many

What I’d Do Differently

  • Start with analytics: Would have loved to understand usage patterns better
  • Build community earlier: Creating a Discord or feedback channel
  • Consider monetization sooner: Ran entirely free, sustainability matters
  • More systematic testing: Ad-hoc testing missed edge cases
  • Localization: Should have supported more languages from start

The Code

Built with modern iOS development practices:

  • 100% Swift (no Objective-C)
  • SwiftUI for all UI
  • Combine for reactive patterns
  • Async/await for concurrency
  • MVVM architecture
  • Protocol-oriented design
  • Unit tests for core logic
  • Git for version control

Code Highlights

Favorite technical achievement: Custom weather particle system that renders realistic rain/snow with 60fps using Metal shaders:

// Simplified example of particle generation
struct RainParticle: Hashable {
    var position: CGPoint
    var velocity: CGFloat
    var opacity: Double
}

// Animated using TimelineView and Canvas
TimelineView(.animation) { timeline in
    Canvas { context, size in
        // Draw hundreds of particles efficiently
        particles.forEach { particle in
            context.draw(particle, at: particle.position)
        }
    }
}

Current Status

Mizzle remains available on the App Store as a free download. While I’ve moved on to other projects, I still maintain it with occasional updates for new iOS versions. It stands as my first successful solo project and proof that one person with an idea and SwiftUI can build something people love.

The project taught me that programming is a tool for creating joy, not just solving problems. Sometimes the most meaningful impact comes from making daily routines a little bit brighter.