iPhone and iPad: Use Mail or Adobe Fill & Sign
On an iPhone or iPad, you can sign documents using the markup feature in the iOS Mail app. If you have a Mac and use Preview to sign documents, your signature will actually synchronize from your Mac to your iPhone or iPad so you don’t have to create it a second time.
This feature is convenient, but it only works if you want to sign documents in the Mail app. For example, you may be emailed a PDF document and you may need to sign it and email it right back.
To do this, you’ll need to receive an email with a PDF file attached, tap the PDF attachment, and click the toolbox-shaped “Markup and Reply” icon at the bottom right corner of the screen while viewing the PDF.
You’ll then be able to add a signature by tapping the signature button at the bottom right corner of your screen. You can also type text and draw on the document, if you like.
When you tap “Done”, the Mail app will automatically create a reply to the email with your signed document attached. You can type an email message and then send the signed document.
While this is convenient, it only works in the Mail app, so it is very limited. If you want to do this from any other app, you’ll need a third-party signing app.
There are quite a few options here, but we like Adobe’s Adobe Fill & Sign app, which allows you to sign an unlimited number of documents for free. It can even capture pictures of paper documents with your camera, so you can create digital copies of paper forms. You can sign a document by writing on your touch screen with a finger or stylus, and they also allow you to type text into PDF documents to fill them in.
To get a PDF document from another app into Adobe Fill & Sign, find the PDF file in another app, tap the “Share” button, and choose the Adobe Fill & Sign app. You can then tap the signature button to easily sign the document. When you’re done, tap the “Share” button within Adobe Fill & Sign to send the signed document to another app.
Android: Use Adobe Fill & Sign
Android doesn’t come with a built-in app that can do this. Instead, you’ll need to use a third-party app. Just like on the iPhone and iPad, we like Adobe Fill & Sign, which allows you to sign an unlimited number of documents a month for free. It can also capture pictures of paper documents with your camera so you can sign them electronically.
After installing the app, you can open PDF documents in the app and tap the signature button to sign them. You can then share the signed document with another app by tapping the “Share” button.