6 Best Signature Apps for iPhone and Android in 2026

A signature drawn on a phone is not automatically a certificate-based digital signature. Most mobile signature apps place a visible electronic signature on a document. A digital signature uses a Digital ID and can help recipients verify the signer and detect changes made after signing. This distinction matters when a contract, government form, or regulated workflow requires more than a visible mark.

This guide compares six current options by the work they actually handle: signing your own PDF, preparing forms, collecting signatures, and managing agreement workflows.

Part 1. Which Signature App Fits Your Workflow?

If your only goal is to put your own signature on a PDF and return it, a local PDF editor is usually the shortest path. If you are the sender and need assigned fields, reminders, signer order, or an audit trail, use a request-based e-signature service.

Part 2. 6 of the Best Document Signing App

1. UPDF Signature App

The UPDF app is a powerful PDF reader, file manager, and signature tool designed for seamless productivity.

With its practical signing features, users can add both electronic and digital signatures to PDF documents effortlessly. For electronic signatures, you can draw, type, or import a signature image directly into your file. The digital signing feature ensures secure, legally-binding signatures, perfect for professional use.

Additionally, UPDF's cross-platform compatibility and signature synchronization allow you to save and reuse your signature across devices, including Windows, Mac, iPhone/iPad, and Android, for a consistent workflow.

Download the UPDF app now and experience hassle-free PDF management and signing on the go!

A key differentiator of Adobe is that it incorporates paper documents. While other apps focus entirely on digitally-created documents, UPDF supports scanning, uploading, and converting hard copies into digital formats. You can then edit the scanned document and correct and sign it.

Similarly, you are not limited to the format of documents that you can apply the e-signature application. For example, you can also sign images in such formats as JPG and PNG.

A notable downside you get with many other e-signature apps is that they mainly focus on providing electronic signature services. UPDF is, however, different. It comes with a full suite of features from document creation and annotation to compression and general management.

In addition, the signature app focuses on the security of the sensitive documents that you deal with.

2. UPDF Sign

UPDF Sign is a web-based online signing platform accessible anytime, anywhere, on any device. Offering features similar to DocuSign, it allows users not only to sign documents but also to send them to recipients and collect their signatures. You can add legally-binding digital signatures, making it quick and secure to sign documents online. Plus, registered users can enjoy a free trial with no credit card required. Click the button below to try it out!

3. PandaDoc

PandaDoc is an electronic signature app best suited for business and other corporate users. The app works on a comprehensive document workflow system via which it oversees all aspects of document use and management. PandaDoc enables you to create documents for business use such as proposals, quotes, and agreements all from scratch. You can also edit and fill these documents from the PandaDoc app.

To prevent any complications arising from document editing, the app offers a tracking tool that records all activity carried out on it. With this feature, users have access to the history of changes in a document. They can then go back in time to check the status of a document at a time. In addition, the app offers standard document templates for someone looking to create files for any purpose.

Other commendable features to look out for on PandaDoc include its seamless drag and drop editor and audit trails. From the above, you can safely guess that PandaDoc was built to fulfill the needs of a business audience. The developers, however, took that further by including a payments support tool. The feature enables users to conduct transactions using payment processors such as PayPal, Stripe, and Square, all from the app's interface.

Nonetheless, a key downside is that it has a poor user interface. Having a wide range of product offerings makes it difficult to navigate the various product sections. Then, the premium plan that contains some of these features is quite expensive.

4. DocuSign

DocuSign is a document-signing app with hundreds of millions of individual and corporate users and an exciting set of features.

Its primary tool is the drawing feature giving users the ability to use freehand to develop their custom signature.

Then, we have multi-file support enabling users to work across Doc, Docx, XLS, TXT and above all, PDF. Thus, no matter what format your document is in, rest assured that you are covered. Additionally, the collaborative tool empowers users to work on the same files together simultaneously. DocuSign provides users with an e-envelope feature to group documents together into a folder, making it possible to incorporate additional information.

Furthermore, there is the "Comments' tool. While concurrently working on documents, there are times when you need to make notes and exchange conversations. You necessarily don't need to fill up your calendar, setting another meeting. You can comment and exchange feedback right from the mobile app.

You also get immediate notifications of comments and access the conversation trail. Other valuable features include “Templates” for preparing documents and the Bulk Send tool. With Bulk Send, users can batch-send a single copy to several persons with just a few clicks.

One of the unique highlights of the DocuSign app is its top-notch focus on security and authentication. For example, when collaborating on a document, the app ensures that the persons signing are the ones you invited to do the signing. Authentication channels include email, SMS, phone, Federated Identity Protection, and third-party authentication using tools from Google or Microsoft, among others.

5. Adobe Acrobat Reader Mobile

Acrobat Reader Mobile can add text, select form controls, create a signature or initials, and place the signature in a PDF. Adobe's current mobile guidance says the workflow can work offline; locally saved data can sync after the device reconnects.

How to fill and sign in Acrobat Reader Mobile

1. Open the PDF in Acrobat Reader Mobile.
2. Select Fill & Sign from the bottom menu.
3. Complete the required text, checkbox, or radio-button fields.
4. Create and place your signature or initials.
5. Check the document carefully before saving the signed version.

Adobe states that signatures and initials become permanent once saved and that the PDF is flattened on save in this mobile workflow. Keep an unsigned original if you may need to revise the form. Users migrating from Adobe Fill & Sign must move old documents manually; the old app's files and signature assets are not automatically migrated.

If your file needs editing or form cleanup before signing, UPDF can keep those PDF tasks and the visible signature in one mobile workflow.

Download UPDF for free to edit, fill, and sign the PDF in one app — installation is free, and Pro removes the trial watermark from exported files.

6. SignEasy

SignEasy is a digital signature app aimed at helping businesses to make the signing process less strenuous. Using SignEasy, you can get legally binding signatures and add custom fields for signees to fill.

Then, there is multi-source integration. Often, the document to be signed may be in a drive platform such as Google Drive, OneDrive, Box, and others. SignEasy makes it possible to edit and manage these documents directly from their apps without requiring you to download them to the app.

A further feature of this free signature app is first-rate user-friendliness as the interface is attractive. But, then, it is seamless to navigate the app. Moreover, you can categorize documents into groups and colour-code the various segments for easy access.

Part 3. Electronic Signature vs. Digital Signature vs. Signature Request

A useful analogy is: an electronic signature is the mark on the page; a digital signature is the mark plus a tamper-evident certificate; a signature request is the delivery and tracking system around the document.

For a local certificate-based workflow, read the complete guide to adding a digital signature to a PDF. If you only need to sign a contract from an Apple device, follow the focused tutorial on how to sign contracts on iPhone.

FAQs

Conclusion

The best signature app is the one that matches who starts the workflow. Use UPDF when the PDF is already on your phone and needs filling, editing, or a visible signature. Use UPDF Sign, PandaDoc, DocuSign, or Signeasy when you need to send assigned fields to other people and track completion. Adobe users should use Acrobat Reader Mobile because the standalone Adobe Fill & Sign app has been retired.

For a one-file mobile workflow, UPDF keeps PDF preparation and signing together instead of making you repair the document in a second app.

Download UPDF for free to prepare and sign your next PDF — installation is free, and Pro removes the trial watermark from exported files.