Real AI agent use cases, with sources and setup prompts

Let an agent operate Android apps on the phone itself

Opposable is an Android app that reads the screen through the accessibility service and taps and types in other apps. Claude, ChatGPT or Codex can drive it from a computer, and with none connected a 2B screen model runs the same loop on the phone with no server.

Free tier1 hourAdvancedSource linked

Source

erikkannike on Hacker News · 2026-10-21 · Project link

Written in our own words. Credit to the original author. Link checked 2026-10-22.

What they did

Opposable is an Android app that reads the screen through the accessibility service and taps and types in other apps. Claude, ChatGPT or Codex can drive it from a computer, and with none connected a 2B screen model runs the same loop on the phone with no server.

Result (as claimed)

The on-device agent opened the Clock app and switched to the stopwatch on its own.

Tools they used

ClaudeChatGPTOpenAI CodexAndroidllama.cpp

Cost: OpenAI Codex: free plan, paid from $8/mo. Checked 2026-10-14.

Set it up

  1. Map the task

    Write the trigger, the inputs, the decisions and the output. Note which steps need a human yes.

  2. Connect the tools

    Set up Claude, ChatGPT, OpenAI Codex, Android, llama.cpp with the narrowest permissions that work. Use a test account or sandbox first.

  3. Build the workflow

    Create the steps in order. Add an approval step before anything sends, pays or deletes.

  4. Run it on real but low-stakes data

    Run a few times, read every output, and fix prompts or rules that misfire.

  5. Schedule and monitor

    Turn on the schedule or trigger, and add a daily summary or alert so you notice failures.

Copy the full setup prompt

Paste into your agent and it will walk you through the setup, asking before anything that sends, posts or spends.

You are helping me set up this AI use case end to end in Claude Code.

Goal: Let an agent operate Android apps on the phone itself
What the original author did: Opposable is an Android app that reads the screen through the accessibility service and taps and types in other apps. Claude, ChatGPT or Codex can drive it from a computer, and with none connected a 2B screen model runs the same loop on the phone with no server.
Reported result (as claimed by the author): The on-device agent opened the Clock app and switched to the stopwatch on its own.
Source: https://news.ycombinator.com/item?id=50180190
Tools they used: Claude, ChatGPT, OpenAI Codex, Android, llama.cpp
Category: Automation & business

Please:
1. Ask me 3 short questions about my situation (accounts I have, budget, what I want the output to look like).
2. Propose a step-by-step plan using these tools or cheaper alternatives, with the time and cost of each step. Use official pricing pages; say "check pricing" if unsure.
3. Then do the setup with me one step at a time, waiting for my OK before anything that sends messages, posts publicly, spends money or deletes data.
4. Finish with a checklist to run it again next time.

The Daily 5

Get five new use cases tomorrow morning

Free. Real sources. Unsubscribe any time.

Guides for this use case

How to control coding agents from your phone · How to use Claude Code and Codex together · How to build an iPhone or Android app with AI · How to use ChatGPT for real projects and everyday tasks

Related use cases