From a Jens challenge to a working AI music app.

Prompto Sumo started as a gag after Jens challenged Daniel Düsentrieb to turn his music-generation deck into a real app. This is the proof: a free Suno prompt workshop built with an AI coding-agent workflow.

This is not a music SaaS. It is a public promotion experiment for fast AI prototyping, BYOK workflows, and practical app development.

Try the Studio Discuss your AI prototype

Challenge proof

Built in one day from a challenge

Based on an idea by Jens Henneberg

Free BYOK demo, not a paid music SaaS

Proof of an AI coding-agent workflow

Prompting engineOpenAI-compatible BYOK settingsSuno BYOK executionSong workspacesLyrics and style refinementLocal-first library

For founders and SMEs

Want a prototype like this for your business?

Use Prompto Sumo freely. If this one-day build sparks an app, automation, or AI-agent idea, we can talk about turning your rough concept into a working prototype.

Clickable prototypes from rough ideasInternal tools and workflow automationAI coding-agent product experimentsPractical AI enablement for SMEs

Open cards · why this app exists

Prompto Sumo is also a live promo — and dogfood — for TesterPayKit.

We play with open cards: this app carries the SDK of TesterPayKit, our crowd-testing platform. Prompto Sumo is where we use it on ourselves first — an early experiment to learn, hands-on, how real testing and feedback flow through a shipped product. We're still figuring it out, and we'd rather say that out loud than pretend otherwise.

So feedback, reactions, and questions are welcome — for both Prompto Sumo and TesterPayKit. The in-app bug-reporting tools are reserved for registered TesterPayKit testers, so every report comes from a real, accountable account. Want to help test Prompto Sumo — and see how TesterPayKit works from the tester side? Become a tester. Curious about testing your own app with real people? Just reach out.

Become a tester →Visit TesterPayKit ↗Send feedback or a request

A moinsen experiment. Built with an AI coding-agent workflow — three birds, one app: ship Prompto Sumo, dogfood TesterPayKit, and invite real testers.

Shameless plug · the machine behind the toy

You came for free songs. Stay for the machine that made them.

Prompto Sumo was built in one day by one human — Daniel Düsentrieb (a.k.a. Ulrich Diedrichsen) — running an AI orchestra. Same workflow, same speed, ships everything below. Here's the rest of what came off the line.

The main act

TesterPayKit

Test your app →

Real testers. Real bugs. Or let AI test it.

The crowd-testing platform this very app dogfoods. Get your app tested by everyday people — or by AI testers with profiles. Registered testers get in-app reporting tools right here.

moinsen.dev

See the machine →

One human. An AI orchestra. A portfolio of real products.

The studio that shipped Prompto Sumo in a day — solo, build-in-public, no slide decks. This is the machine.

moinsen KMU

AI für den Mittelstand →

Wissen Sie, was Ihrem Unternehmen entgeht?

Kostenlose AI-Tools für den Mittelstand (DACH) — Digitalisierungs- und Website-Checks, ohne Anmeldung.

Bonblick

See Bonblick →

Foto machen. Bonblick versteht den Rest.

Snap a receipt, see your real spending patterns — privacy-first, no tracking, no ads. A sister app, also a TesterPayKit dogfood.

Ulrich Diedrichsen

Meet Daniel Düsentrieb →

Software wird von Menschen benutzt, nicht von Modellen.

The human behind all of it — Hamburg indie builder, solo founder of moinsen. A.k.a. Daniel Düsentrieb, the one Jens challenged.