Posting this here since .biom is QIIME 2's native feature-table format and I'd guess most people who'd want this tool are already in this community.
biom-viewer is a native macOS app for opening and browsing .biom files without converting them first. The usual routes (biom convert to TSV, loading into pandas/Excel) densify the sparse matrix before displaying anything - fine for a small test table, painful for a real feature table with thousands of features and samples. biom-viewer keeps the matrix sparse and only densifies what's on screen, so it opens instantly and stays responsive at any size.
Also included: switching between the count table and sample/observation metadata views, stacked metadata filters, per-row/column summary stats scoped to your current filter, and combined ID/metadata search.
Free, MIT-licensed, Apple Silicon macOS builds available now: GitHub - yarintm/biom-viewer: Instant, lazy-loading viewer for .biom files — never densifies the full sparse matrix. Native desktop window via pywebview. · GitHub
I built this because I wanted a quick way to eyeball a feature table between pipeline steps without leaving the GUI - curious whether that's a real enough itch for others here, and happy to take feature requests.