Ethan Marshall

Hi! 👋 I'm a Ph.D. student in Computer Science at the University of Miami, where I research conversational AI safety and trust! I'm interested in development for Apple platforms, agent monitors, also Pokémon! Feel free to shoot me an email or connect on LinkedIn.

Projects & Experience

Below are my personal and work projects, listed from newest to oldest; feel free to ask about anything or try some of them out on the App Store! Developer page

2026

Money Can't Buy Agreement: Inspector for LLM Counseling Monitors

Ethan Marshall, Ubbo Visser, Christine Lisetti

Workshop Paper In Progress

An AI counselor in a live session needs a monitor that catches broken rules as they happen, and the usual monitor, a large language model acting as a judge, is slow and expensive. This paper asks which quick, inexpensive checks can do that job as well as an expert would. It puts a range of labelers, from small local models to frontier LLMs, against motivational-interviewing conversations coded by experts, and trusts each one, label by label, only where a confidence bound puts its error rate at an expert's level. An inspector interface replays sessions from the AnnoMI dataset through the eEVA virtual counselor and shows what each choice would mean for speed and cost.

  • Each monitor is certified label by label, only where its error rate is at an expert's level
  • A mix of quick local models and stronger LLMs instead of one frontier model for everything
  • An inspector interface for seeing the speed and cost of each choice in the eEVA virtual counselor
  • Workshop paper in progress for HUMANE-LLM at ACM IUI 2027 (Helsinki, February 2027), available on request

Conversational AI safety

My Ph.D. research at the University of Miami, advised by Dr. Ubbo Visser.

Conference Paper Under Blind Review

I work on what happens when a language model is deployed somewhere the stakes are human, like a counseling or companion chatbot. That means instruments, built with clinicians, that measure whether a model is actually following the protocols a good counselor would, and lightweight monitors that catch problems during a conversation instead of in an audit afterward. I'm advised by Dr. Ubbo Visser in the Department of Computer Science.

  • Clinician-validated fidelity instruments adapted for machine-generated text
  • Lightweight runtime monitors that flag protocol violations during a conversation, not in an audit afterward
  • First-author paper under review (2026), available on request

Swift Student Challenge

Three winning entries, three years apart. Apple picks a few hundred student projects a year; these were three of them.

University of Miami coursework

Graduate coursework from the first year of the Ph.D.: an automated theorem prover in Prolog, 3D models for robotics from photos, and a set of AI search and game worlds.

DYTM

"Do You Trust Me": a deterministic verification layer for LLM code generation, with property-based-test contracts between what you ask for and the code you get.

GitHub Python

Liftgraph

A super simple, ad-free lifting tracker with weight charts and rest timers.

App Store v1.0

2025

Chorale

Playing tests for music teachers: assign once, sync everywhere, including Google Classroom.

App Store v1.0.0 Web gochorale.com

Chorale lets music teachers assign playing tests, collect recordings, and export grades in one place. The iOS app goes beyond the browser with on-device recording and App Clips that open an activity in seconds, and everything stays in sync with Google Classroom.

  • An iOS app and a web app at gochorale.com
  • Deep sync with the Google Classroom API
  • App Clips launch an activity without installing anything

delt

An experiment in multi-agent software development with a corporate-style hierarchy of agents.

GitHub JavaScript

FBFD

A field reference app built for the Franklin-Bingham Fire Department in Michigan.

App Store v1.1.0 Google Play v1.1.0

A custom React Native app for the Franklin-Bingham Fire Department in Michigan, built front end to back end, that gives firefighters one-tap access to the phone numbers, locations, and data they need on a call.

  • 300+ critical data items with quick actions for calls and directions
  • Usability-tested with firefighters, deployed through iOS and Android enterprise distribution
  • Admin roles for managing shared content and access

The Mood Meter

Log how you feel on a two-axis color grid, straight into Apple Health.

App Store v1.1

2024

University of Michigan coursework

27 course projects from my CS degree, each with its own icon, from seam carving and a MapReduce to a search engine.

GitHub Full List

Dynamic Project Management Lab

Research software for Dr. SangHyun Lee's lab at Michigan: a wearable fatigue monitor, a creativity study app, and sensor tooling.

GitHub fatigue-monitor

2022

CORE

A clinical-research access platform. First place at the Michigan Ross Business+Tech Innovation Jam and a U-M Center for Entrepreneurship Fuel Award.

Ross Innovation Jam 1st Place LinkedIn Read More

CORE connects people to clinical research. Researchers publish studies on the web or in the apps, and participants find studies that fit them through a matchmaking system. I co-founded it and led the engineering.

  • 1st place, Michigan Ross Business+Tech Innovation Jam ($7,000)
  • U-M Center for Entrepreneurship Fuel Award ($7,500)
  • SwiftUI apps and a Next.js platform

Metrics for Product Zone

Track your Apple Retail sales metrics, with an Apple Watch app for logging on the go.

App Store v2.0 GitHub Swift

2021

Neodex

A Pokédex for Apple platforms: species, moves, items, Abilities, and a team builder.

GitHub Swift

StreakPal

Reminders that whisk you to Snapchat before a streak slips away.

App Store v1.2 GitHub Swift