Android Large Screen Apps: 5 Essential Best Tips

The Ultimate Guide to **Android Large Screen Productivity** with the Cahier Sample App

In the evolving landscape of mobile technology, the user experience is no longer confined to traditional phone screens. The rapid adoption of tablets, foldables, and Chromebooks has created a significant trend toward large-screen devices, fundamentally changing user expectations. Users now demand applications that are not just scaled-up phone UIs, but are truly adaptive, powerful tools that leverage the extra screen real estate. This presents a significant challenge for developers: how to build applications that deliver exceptional **Android large screen productivity** and creativity without creating separate, complex codebases. The solution lies in a modern approach to development, and Google has provided a definitive blueprint: the Cahier sample app. This article offers a deep dive into Cahier, exploring how it serves as a masterclass in building next-generation Android applications optimized for productivity on any screen size.

Cahier is a comprehensive, open-source note-taking application designed to showcase best practices for creating versatile and powerful user experiences. It’s a go-to reference for developers aiming to enhance **Android large screen productivity**, demonstrating how to effectively integrate text, drawings, and images into a fluid, intuitive interface. By dissecting this sample, you’ll gain practical insights into leveraging powerful tools like Jetpack Compose, the new Ink API, and adaptive UI components to build apps that users will love on their tablets and foldables.

💡 What is Cahier? A Technical Overview

Cahier, which means “notebook” in French, is far more than a simple demo. It is a fully-featured sample application architected to be a canonical example of modern Android development. Its primary purpose is to provide developers with a clear, functional, and well-documented codebase that solves the common challenges associated with building for larger displays. It is a powerful learning tool for anyone serious about improving their app’s **Android large screen productivity** capabilities.

Core Specifications and Architecture

Cahier is built on a foundation of modern, recommended technologies and architectural patterns. This ensures the app is not only performant and scalable but also easier to maintain and extend.

• Language and UI Toolkit: The entire application is written in 100% Kotlin and utilizes Jetpack Compose for its declarative UI. This modern toolkit is instrumental in building the app’s dynamic and adaptive layouts.
• Architecture: It follows an offline-first architecture using the Room persistence library. All notes and drawings are saved locally, ensuring the app is fully functional even without an internet connection. This is a critical feature for any productivity app.
• Adaptive Components: Cahier leverages the Material 3 Adaptive library 🔗, a collection of specialized composables designed to make building responsive UIs straightforward.
• Modern APIs: The sample is a showcase for powerful new APIs that directly contribute to a superior **Android large screen productivity** experience, including the Ink API for low-latency drawing, a robust Drag and Drop implementation, and deep system integration via the Android 14 Notes Role.

Primary Use Cases for Developers

Developers can use Cahier as a reference for several key implementation goals:

• Building Adaptive Layouts: Understand how to use window size classes and adaptive scaffolds to create a single layout that works beautifully on phones, tablets, and foldables.
• Implementing Advanced Input: Learn the correct way to integrate high-performance stylus and touch input for drawing and handwriting using the Ink API.
• Mastering Window Management: See a practical example of supporting multi-window and multi-instance modes, allowing users to work on multiple documents side-by-side.
• Deep System Integration: Discover how to register an app for the Notes Role, enabling it to be launched from system-wide entry points for quick content capture. This is a key driver for **Android large screen productivity**.

⚙️ Feature Deep Dive: The Pillars of Cahier

Cahier’s excellence stems from its thoughtful implementation of features that directly address the needs of users on large-screen devices. Let’s analyze the core components that make it a standout example of **Android large screen productivity**.

A Foundation of Adaptivity with Material 3

The cornerstone of Cahier’s UI is its adaptivity. The app seamlessly transitions its layout based on the available screen space. This is achieved primarily through two powerful composables from the Material 3 Adaptive library:

• ListDetailPaneScaffold: This component is the workhorse for the app’s main screen. On compact screens (like a phone in portrait mode), it displays only the list of notes. On larger screens with more horizontal space, it automatically shows a two-pane layout with the note list on one side and the selected note’s content on the other. This pattern is fundamental to effective **Android large screen productivity**.
• NavigationSuiteScaffold: This handles the app’s top-level navigation. It can intelligently switch between a bottom navigation bar, a navigation rail, or a permanent navigation drawer depending on the window size class, ensuring ergonomic and efficient navigation across all devices.

Natural Inking with the Ink API

Stylus support transforms a tablet into a digital canvas. The Ink API 🔗, now in beta, is a cornerstone of Cahier’s creative capabilities. It provides a modular and highly performant solution for rendering ink strokes with incredibly low latency. The API is broken down into several logical modules:

• Authoring: Cahier uses the InProgressStrokes composable to handle real-time stylus or touch input, rendering the “wet” ink with the lowest possible latency the device can offer.
• Strokes & Rendering: Once a stroke is completed, it becomes an immutable Stroke object. The CanvasStrokeRenderer is then used to efficiently draw these “dry” strokes onto a Compose Canvas.
• Brushes & Geometry: The API provides a declarative way to define brushes (pens, highlighters) and perform geometric calculations, such as hit-testing for the eraser tool, making the drawing experience feel intuitive and precise.
• Storage: The storage module provides highly efficient functions to serialize and deserialize ink data, drastically reducing the storage footprint compared to formats like SVG or JSON, which is crucial for an offline-first app.

Seamless Drag and Drop for Content Integration

A key aspect of **Android large screen productivity** is the ability to move content seamlessly between applications. Cahier demonstrates a robust drag-and-drop implementation. Users can drag images from a web browser or photo gallery and drop them directly into a note. This is not just a novelty; it’s a workflow accelerator that users on large-screen devices expect. The sample code provides a clear guide on how to handle both incoming content URIs and how to configure your own app’s content to be draggable to other applications.

🚀 Implementation Guide: Bringing Cahier’s Concepts to Your App

Understanding the theory is one thing; implementing it is another. This section provides practical code examples inspired by Cahier to help you get started with building for better **Android large screen productivity**.

Setting Up an Adaptive Layout

To create a responsive list-detail view, you can use ListDetailPaneScaffold. The core logic involves providing the scaffold with your list pane, your detail pane, and the current navigation state.

First, ensure you have the Material 3 Adaptive dependency in your `build.gradle.kts` file:

implementation("androidx.compose.material3:material3-adaptive:1.0.0-alpha06")

Next, you can implement the scaffold in your UI. This simplified example shows the basic structure:

@OptIn(ExperimentalMaterial3AdaptiveApi::class)
@Composable
fun NotesScreen(
    // ... other parameters
) {
    // Calculate the scaffold directive based on window size
    val scaffoldDirective = calculateStandardPaneScaffoldDirective(currentWindowSize())

    val navigator = rememberListDetailPaneScaffoldNavigator(
        scaffoldDirective = scaffoldDirective
    )

    ListDetailPaneScaffold(
        directive = navigator.scaffoldDirective,
        value = navigator.scaffoldValue,
        listPane = {
            // Your Composable for the list of notes
            NoteList(
                onNoteClick = { noteId ->
                    // Navigate to detail pane, showing it if space allows
                    navigator.navigateTo(ListDetailPaneScaffoldRole.Detail)
                }
            )
        },
        detailPane = {
            // Your Composable for the note detail view
            NoteDetail(
                // ...
            )
        }
    )
}

This declarative approach, central to Jetpack Compose, massively simplifies the process of building UIs that support all form factors, which is a huge win for **Android large screen productivity**. For more details, see our guide on Jetpack Compose.

Integrating the Ink API for Drawing

Adding a drawing canvas with the Ink API is remarkably straightforward. The InProgressStrokes composable handles the complex work of capturing pointer events and rendering low-latency strokes.

@Composable
fun DrawingCanvas(
    viewModel: DrawingViewModel
) {
    val state by viewModel.uiState.collectAsState()

    DrawingSurface(
        modifier = Modifier.fillMaxSize()
    ) {
        // Render the "dry" strokes that are already saved
        CanvasStrokeRenderer(strokes = state.strokes)

        // Handle real-time "wet" ink input
        InProgressStrokes(
            brush = state.currentBrush,
            onStrokesFinished = { strokes ->
                viewModel.addStrokes(strokes)
            },
            // ... other parameters like input handling
        )
    }
}

The ViewModel is responsible for managing the state, such as the list of completed strokes (`state.strokes`), the currently selected brush (`state.currentBrush`), and the logic for the undo/redo stack. This clean separation of UI and logic is a hallmark of modern Android architecture. Explore the official Cahier GitHub repository to see the full implementation.

📊 Performance & Benchmarks: Why Modern APIs Matter

High performance is not just a “nice-to-have”; it’s a core requirement for a positive user experience, especially in productivity and creativity apps. Cahier’s use of modern APIs provides measurable benefits.

Drawing Latency and Storage Efficiency

The Ink API is heavily optimized for performance. Here’s a conceptual comparison of its impact:

The analysis is clear: leveraging the Ink API directly translates to a better product. The low latency makes the digital pen feel like a real one, and the storage efficiency ensures the app remains fast and lightweight, even with thousands of notes. Optimizing these metrics is critical for achieving excellent **Android large screen productivity**.

scenarios Use Case Scenarios: **Android Large Screen Productivity** in Action

To understand the real-world impact of an app like Cahier, let’s consider a few user personas.

• The University Student: Using a tablet with a stylus, a student takes notes during a lecture. They use Cahier’s multi-window support to have their textbook PDF open on one side of the screen and a fresh note on the other. They use the Ink API to quickly sketch diagrams and annotate screenshots dragged in from a web browser. The result is a rich, interactive set of notes that enhances learning and retention.
• The UI/UX Designer: A designer uses a foldable device to quickly brainstorm app layouts. On the large inner screen, they have a spacious canvas to sketch wireframes. When an idea is ready, they can select the drawing and drag it directly into a Slack or Teams conversation to share with colleagues for instant feedback. This accelerates the creative workflow.
• The Project Manager: Working on a Chromebook, a project manager utilizes Cahier’s multi-instance capability. They open two separate notes side-by-side in different windows—one for meeting minutes and another for their personal to-do list. This desktop-class multitasking is a prime example of superior **Android large screen productivity**.

⭐ Expert Insights & Best Practices for Development

The Cahier sample embodies several key principles of modern Android development. Adopting these best practices will help you build higher-quality applications for all screen sizes.

1. Design for Adaptivity from the Start: Don’t treat large screens as an afterthought. Use window size classes and adaptive components as the foundation of your UI. A responsive design is the first step toward great **Android large screen productivity**. Read more in our tablet optimization guide.
2. Embrace Platform APIs: Leverage modern APIs like Ink, Drag and Drop, and WindowManager. They are highly optimized and provide the functionality that users on large screens expect. Reinventing the wheel is often less performant and leads to a non-standard user experience.
3. Profile and Test Relentlessly: Use the powerful tools in Android Studio, such as the Layout Inspector and Profiler, to identify and fix performance bottlenecks. Test your app on a variety of form factors using the resizable emulators for phones, tablets, and foldables.
4. Integrate Deeply with the System: Implement features like the Notes Role to make your app an integral part of the user’s workflow. Deep integration reduces friction and makes your app the go-to choice. Learn more about what’s new in Android 14.

🧩 Integration & Ecosystem: Tools of the Trade

Building an app like Cahier is a team effort between you and the robust ecosystem of Android development tools. Effective **Android large screen productivity** is built upon this strong foundation.

• Android Studio: Essential tools like the resizable emulator (including Pixel Tablet and Pixel Fold profiles), motion layout editor, and live edit for Jetpack Compose are indispensable for rapid development and testing.
• Jetpack Libraries: Cahier relies heavily on the Jetpack suite. Room handles the database, Navigation manages UI flow, and ViewModel preserves state across configuration changes. Mastering these is key to building robust apps. Check out our Room database best practices.
• Material Design 3: Beyond just adaptive components, Material 3 provides a complete design system, including support for dynamic color, which allows your app’s look and feel to adapt to the user’s wallpaper and themes. Our Material 3 guide has more info.

❓ Frequently Asked Questions (FAQ)

1. What is the main purpose of the Cahier sample app?
Cahier is an open-source sample app from Google designed to demonstrate best practices for building modern Android applications that excel in productivity and creativity, especially on large screens like tablets and foldables. It’s a reference for implementing adaptive UIs, low-latency inking, and multi-window support.

2. Which version of Android is required to use all of Cahier’s features?
While the app is designed to work on a range of Android versions, some of the most advanced features, like registering as the default app for the Notes Role, require Android 14 (API level 34) or higher.

3. Is the Ink API only for stylus input?
No. The Ink API is designed to work seamlessly with both stylus and touch input, allowing developers to create rich drawing experiences for all users, regardless of whether they have a dedicated stylus.

4. How does Cahier handle offline data storage?
Cahier uses an offline-first architecture built on the Jetpack Room persistence library. All notes, text, and drawing data are stored in a local SQLite database, ensuring the app is always functional.

5. Can I use the code from Cahier in my own commercial app?
Yes. The Cahier sample app is provided under the Apache 2.0 License, which allows you to freely use, modify, and distribute the code in your own personal and commercial projects.

6. What are the key libraries used for building Cahier’s adaptive UI?
The adaptive UI is primarily built using the `material3-adaptive` library, specifically the `ListDetailPaneScaffold` and `NavigationSuiteScaffold` composables, which automatically adjust the layout based on window size classes.

7. Why is multi-instance support important for **Android Large Screen Productivity**?
Multi-instance support allows a user to open multiple, separate windows of the same app. This is a crucial productivity feature on large screens, as it enables true multitasking, such as comparing two documents or referencing one note while writing another, mimicking a desktop workflow.

🏁 Conclusion & Your Next Steps

The shift to large-screen devices is one of the most significant trends in Android development today. Users expect more, and tools like Jetpack Compose and the Ink API, showcased brilliantly in the Cahier sample app, provide the power to meet those expectations. Cahier is more than just sample code; it is a clear, practical guide for building the next generation of applications focused on world-class **Android large screen productivity**. By embracing adaptive design principles, leveraging modern APIs, and prioritizing performance, you can create experiences that delight users on any device.

Your journey to mastering **Android large screen productivity** starts now. We encourage you to dive in:

• Explore the complete Cahier source code on GitHub.
• Clone the repository and run the app in Android Studio to experience its features firsthand.
• Begin incorporating these patterns and best practices into your own applications today.
• Learn more about advanced windowing with our deep dive into the WindowManager API.

By building on the foundation that Cahier provides, you can ensure your app is not just ready for the future of Android—it’s defining it.