A big unfolded screen makes reading possible; a few settings make it comfortable. This page is the short tour of every reading-comfort control in FoldRender — the Reading sheet, the code wrap toggle, outline navigation, the find bar and per-document scroll position — what each one does, and which to change once and never think about again.
FoldRender is on the Play Store as FoldRender: Repo Reader, package id dev.foldrender.app, free and distributed worldwide. Install it the ordinary way — no allow installs from this source prompt to approve, and updates arrive on their own. The app declares minSdk 30, so it needs Android 11 or newer; Play will tell you if a device is below that rather than letting you install a build that cannot run.
The text-size icon opens the Reading sheet, which has four controls: a Theme segmented control (System / Light / Dark), a Text size slider from 80% to 160%, a Line width slider from 480 dp to 1200 dp, and a Serif body text switch. The settings persist across documents and sessions, and changing the theme re-renders without re-parsing the document — so toggling dark mode mid-read is instant.
Line width is the setting that matters most on an unfolded Fold. Without it, paragraphs run the entire width of the inner screen and your eyes lose the line on every return sweep. Cap the measure somewhere short of full width — a comfortable column rather than a banner — and long Markdown pages suddenly read like pages. This is the one control most reading apps omit and the one that pays off immediately.
Source files have their own control: a Wrap chip next to the file header. Off, long lines scroll horizontally with the line numbers staying aligned; on, they wrap into the reading column. Folded, wrapping is usually what you want — horizontal scroll on a narrow screen fights the reader. Unfolded with a two-pane layout, horizontal scroll often reads better because the code pane is already the width you chose.
In a rendered Markdown document, a small floating button in the bottom-right corner opens an outline sheet listing the document's top-level headings, with the one you are inside emphasised; tap a heading to scroll there. Long documents stop being scroll-bar problems. A document with no headings gets “No headings in this document.”
The magnifier in the top bar opens the find bar — placeholder Find in document…, a live current/total match counter, and up/down chevrons to step through hits. It appears for text-shaped formats: Markdown, notebooks, JSON/YAML/TOML, CSV, source, logs and plain text. PDFs, images and HTML have no find bar — in a PDF your navigation is the page counter and the tap-to-jump thumbnail strip.
Scroll position is stored per document and restored when you reopen it, so moving between three files and back does not lose your place in any of them. Combined with the Recent tab and long-press favourites in the tree, a multi-document reading session survives interruptions without any bookmarking ceremony.
The Markdown parsers emit no colours and no Compose types — that is why switching theme re-renders without re-parsing. Dark mode mid-chapter costs a relayout, not a re-walk of the document.
In a PDF, the Reading sheet's theme applies to the app shell around the document, and page bitmaps are cached per page and per width — so rotating or refolding re-renders pages at the new width instead of upscaling a stale bitmap.
Text size is the obvious knob; line width, wrapping and outline navigation are the three that actually decide whether a two-hour read on a folded-out phone feels like reading or like scanning.
The honest list — shipped-but-unverified behaviour included, so you can tell before installing whether this build does the thing you came for.