OpenDisplay vs Bifolium

OpenDisplay turns your iPhone or iPad into a second display for your Mac. It's the open-source way to put your spare Apple device to work as a real extended monitor — drag windows onto it, keep chat, notes, or logs in view, and gain screen space anywhere you go. It's not a mirror: it's a genuine additional display your Mac treats like any other monitor. • Real extended display — arrange it in your Mac's Display settings and drag windows across • Connect over USB for the lowest latency, or over Wi-Fi with zero setup • Retina-sharp, pixel-for-pixel rendering • Touch and scroll — tap, drag, and two-finger scroll to control your Mac • Works in portrait or landscape • Private by design — a direct connection between your own devices, with no accounts, no servers, and no tracking IMPORTANT: OpenDisplay requires the companion OpenDisplay app for Mac, running on your computer on the same cable or Wi-Fi network. Get it at https://peetzweg.github.io/opendisplay — without it, this app has nothing to connect to. OpenDisplay is open source under the GPL-3.0 license. Read the code, report issues, or contribute at https://github.com/peetzweg/opendisplay

Bifolium reads and annotates Markdown, from your own files or straight from GitHub. Open a document on iPhone, iPad, or Mac and Bifolium reads it where it is, without importing or converting it. Bifolium detects the Markdown a document is written in and renders it correctly: CommonMark, GitHub Flavored Markdown, and Obsidian's flavor with wikilinks, callouts, and YAML frontmatter. Tables, images, footnotes, TeX math, and Mermaid diagrams render offline. Code is highlighted in more than 30 languages. Highlight a passage and note a thought beside it. Both are kept apart from the document, so reading never changes the file. Find them again across every document, or start from one highlight and see related passages from your other files. Matching runs on your device. Save GitHub repositories, public or private, as read-only snapshots you can read offline and refresh when you choose. On a Mac, pick files or folders to carry to iPhone and iPad through your own iCloud; highlights, notes, and reading position stay in step. Bifolium edits, too. When a file needs a change, open it in Source or Live Preview and save it in place. Four themes come built in, or make your own. Set type size, line height, text width, margins, and paragraph spacing. Export a document to PDF or HTML, or your highlights and notes to Markdown with links back to each passage. Bifolium needs no account. Rendering, search, and matching run on your device. Sync uses your iCloud account, and GitHub connections go directly to GitHub. Anonymous usage counts are on by default: no identifier, no document content. Turn them off in Settings. Your 30-day trial of the whole app starts the first time you open Bifolium. After that, a one-time purchase keeps Bifolium permanently, or pay monthly. If access ends, your originals stay where they are and your highlights and notes remain yours to export. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/