---
title: "Piet Jonas — Publisher Overview"
type: publisher
publisher: "Piet Jonas"
publisher_slug: "piet-jonas"
canonical_url: "https://marlvel.ai/publishers/piet-jonas"
last_updated: 2026-04-24T08:37:33.765Z
source: Marlvel.ai
license: CC-BY-NC-4.0
citation: "Marlvel.ai — Piet Jonas Publisher Overview"
---
## ⚠ Content Warning

This publisher's portfolio includes apps classified as sensitive (finance). Information is aggregated from public sources for informational purposes only. This overview touches financial apps. It is not financial or investment advice.

---

# Piet Jonas — Publisher Overview

> Providing specialized utility tools and calculators for professionals and technical users needing precise, localized data.

- **Publisher:** Piet Jonas
- **Website:** [https://vat.speedymarks.com](https://vat.speedymarks.com)
- **Overview generated:** 2026-04-24
- **License:** CC-BY-NC 4.0

## Executive summary

Piet Jonas operates as a utility-focused studio, prioritizing single-purpose tools over broad consumer platforms. The portfolio's strategic value is concentrated in high-utility calculators and technical viewers that leverage localized data engines, such as international tax rates and solar positioning. This 'build and maintain' approach allows the publisher to occupy specific functional niches in the Shopping and Reference categories with minimal competitive overlap.

## Publisher DNA

- **Primary focus:** Utility tools and specialized calculators
- **Scale:** studio
- **Target audience:** Professionals, web developers, and international travelers requiring specific technical, financial, or environmental data.

## Portfolio momentum

- **Velocity:** steady
- **Active apps:** 5
- **Abandoned apps:** 4
- **Last major release:** 6 days ago

Maintained a steady development cadence with 3 updates across the portfolio in the last 6 months, focusing on core utility functionality.

## Aggregated portfolio metrics

- **Total reviews (all apps):** 3,274
- **Weighted rating:** 4.55 / 5
- **Apps in portfolio:** 12

## Category breakdown

| Category | Apps | Share |
| :--- | :--- | :--- |
| Weather | 4 | 33.3% |
| Games | 3 | 25% |
| Travel | 1 | 8.3% |
| Navigation | 1 | 8.3% |
| Finance | 1 | 8.3% |
| Reference | 1 | 8.3% |
| Shopping | 1 | 8.3% |

## Top apps

- **VAT Calculator** — Portfolio flagship — 2,909 reviews with a 4.6-star rating.
- **Source Viewer** — Technical reference tool with 232 reviews and 4.4-star rating.
- **Solar Time** — Niche weather utility with over 100 reviews.

## Signature patterns

- Focus on single-purpose utility tools with streamlined, functional interfaces.
- Heavy reliance on localized data engines including tax jurisdictions and geographic positioning.
- Hybrid monetization strategy utilizing both free-to-use and paid upfront models.
- Long-term maintenance of legacy titles, with some active apps dating back to 2008.

## Bottom line

Piet Jonas is a disciplined utility publisher that successfully captures niche professional intent through specialized calculation tools. Their portfolio demonstrates strong product-market fit in the Shopping and Reference categories, sustained by a low-churn, utility-first user base.

---
© 2026 Marlvel.ai | [Publisher apps index](https://marlvel.ai/api/llm/publishers/piet-jonas) | [Methodology](https://marlvel.ai/api/llm/methodology)
Data licensed under CC-BY-NC 4.0.

---
© 2026 Marlvel.ai | [Full publisher profile](https://marlvel.ai/publishers/piet-jonas) | [Publisher apps index](https://marlvel.ai/api/llm/publishers/piet-jonas) | [Methodology](https://marlvel.ai/api/llm/methodology)
Data licensed under CC-BY-NC 4.0.