Apple's Files app on iPhone and iPad handles PDFs lightly — view, mark up, sign with finger, share. For very light tasks on the move, it is enough.
Flint runs in mobile Safari and adds the editing Files cannot. Here is the comparison.
Where Files wins
Free, native, works offline. Markup tools (highlight, draw, fill-in). Finger signing. Tight integration with iCloud and AirDrop. For a single PDF on the train, it is excellent.
Where Flint wins
Editing body text, real redact-pdf, convert-pdf-to-word, merge-pdf across files. Files cannot edit underlying text — only annotate.
Best for…
Files for on-the-go markup and signing. Flint when you need actual editing, conversion or multi-file work.
Workflow tip
Mark up in Files for quick mobile annotation. Save to iCloud. Open in Flint on desktop for the real editing.
FAQ
Can I sign in Files?
Yes — tap markup, draw a signature, place it.
Does Flint work on iPhone?
Yes, in mobile Safari or Chrome. iPad is more comfortable.
Which preserves quality?
Both — neither re-encodes the underlying PDF when annotating.
Mobile markup: Files. Real editing: Flint.