Sign PDF Offline · safeBubble

Sign a PDF offline, with your own handwritten signature, on your phone. No account, no sign-in, no subscription and no internet connection — safeBubblePDFsign works in airplane mode, on a plane, or in a room with no signal.

YOUR REAL SIGNATURE, FROM A PHOTOGRAPH

Photograph your signature on a piece of paper. The app lifts the ink off the page — removing the paper, the shadow and the colour cast — and keeps the shape, pressure and taper of the strokes exactly as you wrote them. It never generates or reconstructs handwriting, and there is no drawing tool, because a drawing tool would break that promise.

Clean it up by hand if you need to: erase a stray mark, or restore a stroke the camera nearly missed. Nothing is ever drawn for you.

SIGN THE DOCUMENT, KEEP THE ORIGINAL

Open a PDF, place your signature where you want it, resize it, and export. Your original document is never modified — signing always produces a new file, and the app checks the result before offering it to you. Text, forms and page layout are preserved; nothing is flattened or rasterised.

Initials and a handwritten date work the same way: photograph them once, and they join your signature library to be placed like anything else.

IT WORKS COMPLETELY OFFLINE

There is no account, no sign-in, no subscription, no ads and no tracking. The Android app ships without the internet permission, so Android itself refuses it a network socket. It cannot upload your documents — enforced by the operating system, rather than promised in a policy.

FEATURES

• Sign a PDF offline — no internet connection needed, ever
• Your real handwritten signature, scanned from a photo of paper
• Manual cleanup: erase marks, restore strokes; nothing is drawn for you
• Blue or black ink
• A library of signatures, multiple pages, one export
• Password-protected PDFs open, and stay protected
• Large documents are fast: a 200-page PDF signs in a fraction of a second
• The exported file begins with your source file byte for byte
• Light and dark themes, and 200% text scaling
• One purchase, once. No subscription, no in-app purchases, no ads, no account.

WHO IT IS FOR

Anyone who has to sign a form and would rather not upload it — and anyone whose employer or regulator does not permit documents to leave the device at all.

safeBubblePDFsign places an image of your handwritten signature on a PDF. It is not a cryptographic digital signature, it is not certificate-based, and it makes no claim about legal
validity in any jurisdiction.