Anvil Web App Overview

I'm Nathan, and I made Anvil because I wanted an AI assistant that keeps my things on my phone.

Anvil runs its models on your iPhone. You download Anvil Core over WiFi once, and then you can chat, use voice, and work with your notes, tasks, photos and documents without a connection. There's no account and no login, and your chats stay on the phone. Optional web search and iCloud backup are clearly separate from on device chat, so you always know when something leaves the phone. Anvil Dream, an optional download inside the app, makes 1024x1024 pictures on the phone too.

Things I actually use it for: reading a Japanese train sign from a photo in Airplane Mode, turning a receipt photo into a note with the total, and drafting messages on flights, all with no signal at all.

Who it's for: people who want an assistant that keeps their stuff on their phone, travelers who are often offline, and anyone curious what a phone can do on its own.

How it works: chat uses Gemma 4 E2B running on LiteRT LM, and Anvil Dream is an SDXL Lightning variant in Core ML on the Neural Engine. The two models never load at the same time, which is how it all fits.

Quick tip if you try it: let the Anvil Core download finish on WiFi, then flip on Airplane Mode and ask it something about a photo. That's the moment it clicked for me.

It's in a free public beta on TestFlight right now. Every beta tester gets Anvil Pro free. It requires an iPhone 15 Pro or newer.

I'd love blunt feedback on setup, speed on your phone, and anything confusing. Thank you for testing!

What to try as a tester:

1. Install from the TestFlight link and go through first launch and the Anvil Core download on WiFi. Tell me anything that felt slow, unclear or worrying.
2. Turn on Airplane Mode, take or pick a photo of a sign, menu or receipt, and ask Anvil about it. Was the answer right, and how long did it take on your phone?
3. Optional: download Anvil Dream in the app and make one picture. How long did it take, and did your phone get warm?