Marcel Iseli

I'm an indie app developer and the creator of Batchio. I build native macOS utilities focused on productivity and file management.

Why I Built Batchio

I built Batchio because renaming files on Mac was harder than it needed to be. Finder only handles basic text replacement. Terminal requires memorizing arcane syntax. Existing batch renamers are powerful but feel overengineered for most workflows, and none of them show you results in real time as you build your rules.

I wanted a batch renamer that makes the simple things instant and the complex things possible, with a live preview that updates on every keystroke. Batchio is the result: 9 composable rule types, regex with capture groups, EXIF and audio metadata support, conflict detection, and full undo. All built natively in Swift and SwiftUI.

What Makes Batchio Different?

Batchio is built with native Swift and SwiftUI, not Electron or web views. It launches fast, uses minimal resources, and feels like it belongs on your Mac. The free tier includes all 9 rule types with no feature gates on core functionality. The optional Pro upgrade ($4.99, one time) adds saved presets, folder automation, Finder Quick Action, and Shortcuts integration.

Every design decision follows the same philosophy: respect for the user's time, no data collection, and a clean native experience.

My Other Mac Apps

I build a suite of native macOS utilities, all following the same principles: lightweight, native, and focused on doing one thing well.

MoniThor

Mac menu bar system monitor with live sparkline graphs for CPU, RAM, GPU, battery, network, and disk.

Mouzz

Cursor highlighter for Mac with spotlight effect, ring cursor, click feedback, and cursor trails for presentations and screen recordings.

DupScan

Native macOS duplicate file finder with SHA256 hashing, real time scanning, and system file protection.

Experience and Background

I've been building apps for over a decade, with a focus on macOS and iOS development. I'm passionate about building tools that are lightweight, focused, and respect the user's time. Every product I create follows the same philosophy: native performance, clean design, and no data collection.