Use a tablet or phone to handwrite, annotate and sign on your computer

The useful idea: keep the work on the computer

Handwriting on a Mac or PC does not require moving every file to a tablet. A phone or tablet can be the writing surface while the note, whiteboard, PDF or document stays open in the desktop application.

The computer remains the place where the file is opened, edited and saved. The mobile device shows the selected desktop content and returns your pen or finger movement as input, without creating a second copy to send back later.

Pad uses a host on the Mac or Windows computer and a client on the tablet or phone. It suits a full lesson with a stylus or a quick signature on a phone.

Handwritten notes and desktop whiteboards

For a student, start with a pen-aware note or whiteboard application on the computer and select its pen tool. Put the canvas in the streamed display, window or region, then write on the mobile screen. Course files and keyboard shortcuts remain on the computer.

This is especially helpful for material that is awkward to type: equations, diagrams, arrows, chemical structures, musical notation or a quick sketch beside typed text. A tablet with an active stylus is the better choice for a long lecture because it gives you more room and more precise control. If the stylus and desktop application support it, Pad can deliver pressure-aware pen input as well.

The desktop application is still an important part of the chain. It must accept pen or pointer input, and you must choose an inking, pencil or drawing tool inside that application. Pad cannot add a handwriting mode to software that has none. Some applications treat pen input like a mouse; others understand richer tablet data. Test one short stroke before committing to a whole class of notes.

Teaching, tutoring and working through problems live

A teacher or tutor can keep a whiteboard, slide deck or worksheet open on the computer and write from the tablet while sharing the screen. Circle a term, add a diagram or solve a problem step by step, then use the keyboard or mouse to change slides and resources.

Before the session, increase the page zoom, choose a high-contrast pen colour and leave room for intermediate steps. If you are presenting through conferencing software, verify that it shares the intended window. Preserve a clean problem page and annotate a duplicate, then save or export on the computer.

Marking assignments and annotating documents

The same arrangement works for reviewing homework, commenting on a report or marking a PDF. Open the file in a desktop application with an annotation tool, select it, then write on the tablet. Marks and arrows are often faster by hand; longer feedback is usually clearer when typed.

Before marking many files, test the workflow:

1. Open one assignment and choose its annotation tool.
2. Make a stroke, undo it and check that the pen maps to the correct place.
3. Mark the file, then use the desktop application’s normal save or export command.
4. Reopen the result once to confirm that the annotations were preserved rather than left in an unsaved layer.

Sign a document without sending it to another device

For a quick signature, a phone can be enough. Leave the document open on the computer, activate its signature or ink tool, and use the Android phone as a small input surface. Sign with a finger, inspect and retry if needed, then save on the computer. The file never needs transferring to the phone and back.

Use the application’s signing feature when a formal digital signature is required. A handwritten mark is not automatically a cryptographic signature; Pad supplies input but does not change the meaning assigned by the document software.

Phone and finger, or tablet and active stylus?

Choose for the length and precision of the task rather than assuming the largest device is always necessary.

• Android phone with a finger: practical for one signature, a check mark, a short underline or a quick arrow. The surface is small, so zoom the desktop document and use a reasonably thick stroke. Touch has no pressure data, even when the desktop tool offers pressure-sensitive brushes.
• Android tablet with an active stylus: better for lecture notes, teaching, detailed correction and repeated annotation. More space reduces hand fatigue, while a compatible active stylus offers finer positioning and can supply pressure to desktop software that accepts it.
• Ordinary tablet touch: useful when you need more room than a phone but do not own a stylus. It remains touch input, so expect no pressure and less precise handwriting than an active pen.

If your main goal is illustration rather than handwriting, the hardware and pressure details deserve more attention. See the Android drawing-tablet guide or the focused Krita drawing-tablet guide.

Current Pad availability

The components are at different stages today:

• PadDroid is live and free on Google Play for Android 9 or later. It can use an active stylus or touch, including a finger on an Android phone.
• PadMac is a free direct download for Apple-silicon Macs running macOS 15 or later.
• PadWin is available as a beta for Windows 11.
• PadPad for iPad is coming soon; its App Store link will be added after approval.

You need one computer host and one mobile client. An Android device can connect to either supported host, so you can start now without waiting for the iPad release.

Set up Pad step by step

1. Check the desktop application first. Open the note, whiteboard or document tool you plan to use. Find its pen, draw, annotate or signature mode and confirm it accepts a mouse or existing pen input.
2. Install the host. On an Apple-silicon Mac with macOS 15+, install PadMac. On Windows 11, install the PadWin beta and its listed prerequisites. The complete downloads, permissions and Windows dependency instructions are in the Pad setup guide.
3. Grant the requested host permissions. PadMac needs Screen Recording to show the chosen desktop content and Accessibility to return pen input. Relaunch it after granting both. Follow the setup page’s Windows firewall guidance for PadWin.
4. Install and open the client. Install PadDroid on the Android tablet or phone. Allow the local-network access it needs to reach your computer.
5. Connect the devices. Put them on the same local network and select the discovered host. A USB connection can be useful when available, particularly if Wi-Fi is congested or blocks devices from seeing one another.
6. Choose what to show. Select the desktop display, application window or region containing the writing area. Make sure what you touch corresponds to what you see before beginning important work.
7. Test, then tune the workspace. Select the desktop application’s ink tool, draw a short line, try undo, and save a disposable test. Adjust page zoom, brush width and the captured region until text is comfortable to form and read.

Privacy and a local workflow

Pad’s screen stream and input travel directly between your devices over the local connection. Codonic does not relay or store that content. Preferences and paired-device information are stored on the device, and the host can require a pairing code and revoke remembered pairings.

Other software may still have its own cloud features. For sensitive material, check the desktop application’s storage settings, select only the intended window or region, use pairing on shared networks, and revoke devices that should no longer connect.

Troubleshooting checklist

If the picture appears but writing does nothing, select an ink tool in the desktop application. On Mac, recheck Accessibility permission and relaunch PadMac; after a reinstall, remove stale permission entries and grant them again. Software that does not accept pen or pointer input cannot be made pen-aware by Pad.

If the client cannot find the host, confirm that both devices share a network. Guest, school and office Wi-Fi may isolate devices; try an allowed USB connection or private local network. On Windows, allow PadWin on private networks. If it connects without a picture, check the ffmpeg.exe location described in the setup guide.

If strokes land in the wrong place, restore and reselect the captured window or region. If writing feels cramped, zoom in or use a larger tablet. Choose a thicker, non-pressure-sensitive tool for a finger; with an active stylus, test pressure in a pen-aware app before adjusting curves or smoothing.

Once a test stroke, undo and save all work, the setup is ready for real notes, live explanations, marked assignments or the occasional signature—without changing where the original document lives.