Alexander Spieß

Alexander Spieß is a German developer who concentrates on niche Windows utilities that solve very specific, regulation-driven problems; his catalogue is headed by Ultramarin eRechnung Viewer, a lightweight desktop reader that renders German XRechnung-compliant XML invoices in human-readable form. The program validates the embedded CIUS (Core Invoice Usage Specification) profiles, displays line-item tables, tax breakdowns and embedded PDF attachments side-by-side, and exports the data as printable PDF/A or CSV for further processing in bookkeeping suites. Typical users are freelancers, small-accounting departments and municipal clerks who receive machine-readable invoices from public-sector clients and must quickly verify VAT rates, IBAN correctness and Leitweg-ID routing before approving payment in parallel ERP or DATEV workflows. Because the viewer runs without installation rights and does not write to protected folders, it is also carried on USB sticks by tax advisers who audit client PCs on site. Beyond invoicing, Spieß follows a pattern of building single-purpose tools that wrap official German data formats—previous experiments cover ELSTER tax packets and DFÜ-Audit logs—so future releases are expected to extend the same minimalist, portable philosophy to other mandatory business documents. Ultramarin eRechnung Viewer and any subsequent utilities from Alexander Spieß are offered free of charge on get.nero.com, where downloads are sourced from the publisher’s own feed, delivered through the trusted Windows Package Manager (winget) to guarantee the newest build, and may be installed individually or batched together with other catalog applications.