Smaller, faster, and more powerful: Introducing Code on the Go R2

We are excited to release Code on the Go R2! Since R1 last April, we’ve shipped a new version almost every week, and as a result, CoGo is a very different IDE than it was six months ago; it’s smaller, faster, and more powerful, so you can get your projects to Done! faster. 

As CoGo evolved, we’ve remained committed to our underlying principles: the IDE still runs entirely on your phone, and almost everything still works with no internet connection. 

Here are just a few of the changes.

Smaller downloads

For some of our users, downloading every megabyte costs money, so the size of the CoGo APK matters. Our efforts to decrease APK size have paid off: today’s 64-bit APK is a little less than half the size of R0.

Beyond rigorous optimizations and housekeeping, one way we reduced the size was turning bandwidth-heavy features into optional add-ons. As a result, you can download a lean app that supports the fundamentals, and then add the plugins that you want, such as:

  • The AI Core and AI Agents (including support for local models)
  • Layout Editor
  • Sketch to UI™, which turns a handmade drawing of a screen into a layout

Quick Build: see your change in seconds

Quick Build is one of the biggest changes to how you work in CoGo. Until now, every change meant a full Gradle build and a reinstall, which can take minutes on a phone. With Quick Build, you tap the lightning-bolt button once, and CoGo installs a live version of your app. After that, each time you save a change to your app’s Kotlin or Java code, resources, or assets, the change appears in the running app within seconds. You don’t need to rebuild or reinstall.

In our tests, Quick Build was four to six times faster than a regular build for the same edit. Some changes, like edits to the manifest or Gradle files, still need a full build, which Quick Build handles automatically. Like the rest of CoGo, Quick Build runs entirely on your phone and works offline.

In the video below, we make the same change to the same code on the same phone twice. With Quick Build, the change appears in the running app in 3.4 seconds. With a regular build, it takes 21.8 seconds, more than six times as long. Quick Build is currently an experimental feature, so follow these steps to enable it. 

Kotlin as a first-class citizen

We made greater support for Kotlin a priority in R2. Our Kotlin support now includes:

  • Debugging. You can set breakpoints in Kotlin code, step through it line by line, and inspect variables.
  • Navigation. Go to definition and Find usages work in Kotlin files, and a new outline sidebar shows the structure of Kotlin, Java, and XML files.
  • Help as you type. Kotlin shows parameter hints while you type a function call.
  • Refactoring. New Kotlin code actions include Extract variable, Extract method, Inline variable, Organize imports, Implement abstract members, Surround with try/catch, and null-safety fixes.

Everyday tools got better

Smaller additions every week added up to a much more capable IDE.

  • Git. You can start a Git repository when you create a project or later with one tap. You can also create and switch branches, and select all changed files at once when you commit.
  • Search. “Replace in project” finds and replaces text across your whole project, and you can now search for files from the file tree.
  • Logs. You can filter and search logs and turn on word wrap. To jump to the code that crashed, tap a stack frame in App Logs.
  • Build output. Build output can show timestamps, the time difference between lines, and line numbers.
  • Floating windows. Panels can float in their own movable windows, which helps on tablets and large screens.
  • Performance monitor. Track memory usage, network traffic, temperature, and power usage.
  • “Deep links” to code. To share a spot in your code, you can create a link that opens the exact project, file, and line in CoGo.
  • New toolchain. CoGo now builds with Gradle 9.6.1, Android Gradle Plugin 9.3.1, and Kotlin 2.3.21.
  • Java refactoring tools. New code actions for Extract method, Extract variable, and Surround with try/catch are available.

One place for add-ons

The Add-ons Manager is now the one place to manage everything you add to CoGo. In R1, it handled plugins. Now it handles project templates too, so you can install, update, and remove both from the same screen.

Installing is also simpler. If you open a plugin (.cgp) or template (.cgt) file from your Downloads folder or a chat app, CoGo can install it right away. Settings for plugins are available in CoGo’s Preferences, and a plugin that misbehaves can be turned off instead of crashing the IDE.

Plugins to try

We’ve released more than 20 new plugins since R1! You can find them all in the Add-ons Manager. You need an internet connection to download a plugin, but most plugins then work offline. Here are some highlights.

Online and offline AI

The AI Agent can read your project, explain code, and make changes for you. Install AI Core to get the Agent chat, and then pick a backend:

  • AI Agent Local runs the AI on your phone. Nothing leaves your device, and once you have a model, it works with no internet. To get an offline model, you can use the Get AI Models plugin.
  • AI Agent Claude, AI Agent Gemini, and AI Agent OpenAI connect to online AI services with your own API key. You need an internet connection for these.
  • AI Agent MCP lets the Agent use tools from Model Context Protocol servers.

Three more plugins build on AI:

  • AI Code Suggestions offers inline code completions as you type.
  • Speech to Text converts what you say to written code.
  • Vector Search adds semantic, meaning-based results to CoGo’s project search.
    Code Together

    Pair programming is a core practice in software development, and many development teams rely on pair programming to catch bugs early and write better code. Code Together lets two or more people edit the same project live, each on their own phone. It works over a local Wi-Fi network or one phone’s hotspot, so you don’t need an internet connection or any other kind of network equipment. Instructors who don’t have monitors or projectors can use Code Together to share their screens live with a small class.

    Learn and build

    • AI Literacy Course is a complete Introduction to AI course from Learn AI Anywhere, with 26 videos, activities, and teacher resources. It includes Neuropocket, which lets you train an AI on image recognition, and works fully offline.
    • Bookshelf adds reference books and textbooks to CoGo’s Help section so you can read the resources offline.
    • Python Tools installs Python on your phone and adds Python project templates.
    • cotg ndk gives you a C++ compiler for building native code on your phone. (Thanks to Armin for contributing this plugin!)
    • Project to Template turns any project into a template that you can reuse or share.
    Small tools with big impact
    • Rainbow Brackets colors matching brackets so you can see which ones pair up.
    • Client Time Tracker tracks the time you spend coding for clients and creates invoices.
    • Icons Repository, from community developer Omar Haidar, helps you add icons to your app.

    Get R2 now

    You can always get the latest version of CoGo here on our site.

    View and download add-ons here. You can install them by opening them in the Download folder, or in the CoGo app by going to Preferences → Add-ons Manager.

    We need your support

    App Dev for All is a not-for-profit organization. CoGo and its sister product, Knowledge to Go, are free and open source, but they’re not free to make. If you enjoy our tools or share our vision, please sponsor our work.

    Here are some other ways to support us: