I like note-taking apps that get out of the way quickly, and Squid: Take Notes, Markup PDFs is built around that idea. It is a productivity app from Steadfast Innovation, LLC for writing by hand, working over PDF documents, and sharing the result when needed. The free entry point makes it easy to try, while optional in-app purchases ranging from one dollar to fourteen dollars and ninety-nine cents per item add paid extras for people who want more from the experience.
After spending time with it, my impression is that Squid is most convincing when I treat my phone or tablet like a digital notebook rather than a miniature word processor. The central appeal is the directness of writing with a finger or stylus. I can open a page, write a heading, sketch an idea, underline a sentence, or mark a document without first building a complicated layout. That simplicity also explains its limits: people who mainly type long documents, manage elaborate databases, or need a full office suite may feel more comfortable elsewhere.
How Squid feels during everyday note-taking
Quick starts matter more than flashy extras
The first thing I notice with a handwriting app is how much friction appears before the actual writing begins. Squid has a clear purpose, so the basic workflow feels familiar: create or open a note, choose a writing tool, and put something on the page. That makes it suitable for a lecture, a meeting, a shopping reminder, or a rough plan when typing would interrupt my train of thought.
Its perceived speed is strongest in short sessions. When I need to capture a thought, I do not have to turn it into a polished document immediately. I can write a few lines, circle an important item, and return to it later. This is one reason I would recommend it to students and people who think visually. The page behaves more like paper, so the app supports quick marks instead of forcing every idea into a rigid text field.
That does not mean every task feels equally fast. Handwriting itself can become slow when I am trying to produce several pages of detailed prose, especially if my writing is small or I need to correct many lines. In that situation, a keyboard-first app is usually better. Squid is at its best when speed means capturing information naturally, not necessarily generating a large amount of finished text.
A practical class and meeting workflow
Imagine I am in a class with a PDF handout already available. Rather than switching between a document viewer and a separate notebook, I can use the handout as the surface for my notes. I might highlight a definition, write a question in the margin, and draw an arrow from a diagram to an explanation. Later, those marks remain connected to the original page, which is more useful than having a separate list of comments whose locations I have to remember.
The same approach works in a meeting. I can write action items beside the relevant part of an agenda, mark a decision with a symbol, and share the annotated document afterward. I would still clean up the page before sending it if other people need to read it, because handwritten notes can become visually crowded. The strength is not formal publishing; it is keeping the discussion and my reactions together in one place.
A small habit improves this workflow: I start each note with a visible date or topic label, even when the app already organizes notes for me. Handwritten pages are easy to recognize while I am working, but a clear title makes older material much easier to find. I also leave a little blank space around important diagrams. That gives me room to add a second thought later instead of writing over the original mark.
PDF markup is more useful than a simple pen tool
Many note apps let me draw on a page, but Squid’s PDF-focused workflow changes how I use it. I can approach a document as something to study, review, or prepare rather than merely read. A student can write explanations beside a difficult paragraph. Someone reviewing a form can mark areas that need attention. A designer or project worker can sketch changes directly over a reference document before explaining them to colleagues.
There is a trade-off here. Marking a PDF is excellent for personal understanding and visual feedback, but it is not the same as editing the original document. If I need to change the actual wording, restructure a table, or preserve professional typesetting, I would use a dedicated PDF editor or office application. Squid is better for annotations that show my thinking around the document.
I also find it helpful to separate “temporary thinking” from “final comments.” During a first pass, I use quick arrows and shorthand. Before sharing, I review the pages and remove marks that only made sense to me in the moment. This two-pass method keeps the app useful for both private study and a cleaner handoff, without pretending that handwritten markup automatically becomes polished documentation.
What happens when notes become large?
Light notes and a few annotated pages are the kind of workload where I expect Squid to feel most comfortable. The experience becomes more demanding when I combine long handwriting sessions, many pages, imported documents, and repeated editing. Even without assigning a benchmark, it is sensible to treat a large digital notebook differently from a single reminder: organization and recovery become just as important as pen response.
For heavy use, I would divide material by subject, project, or meeting series instead of keeping everything in one endless notebook. That makes individual notes easier to handle and reduces the chance that an important page gets buried. I also avoid turning every quick thought into a separate decorated document. The app is more pleasant when I use its notebook qualities deliberately rather than trying to recreate an entire filing cabinet inside it.
People who keep extensive handwritten archives should also think about how they will retrieve information. Handwriting is comfortable for recording, but it is not automatically as searchable or editable as typed text. If future search is essential, I would type a short summary or a few keywords at the top of each note. That extra minute can save much more time later.
Stability and recovering from interruptions
A note-taking app earns my trust when I can return to a page after an interruption without losing the context of what I was doing. In normal use, Squid’s focused design supports that kind of continuity: the app is centered on the page, the writing, and the document being reviewed. Still, I do not treat any mobile note as the only copy of something important. Before a deadline or a meeting, I share or export the finished material so there is a separate copy available.
This is especially important for annotated PDFs. My preferred routine is to finish a review, inspect the pages, and create a shareable version before closing the task. I do not wait until the document is urgently needed. That habit is less about expecting failure and more about reducing the consequences of a lost, misplaced, or unfinished working copy.
Recovery also depends on how carefully I work. If I am making substantial changes, I pause after a meaningful section instead of filling many pages without checking the result. I keep the original PDF separate from my annotated version when the source matters. That way, a rough markup session remains reversible and I can begin again without searching for the clean document.
Resource demands and device limitations
Squid is available as a free app for everyone, and its broad audience includes casual users as well as people who write regularly. In practice, the quality of the experience depends heavily on the device. A larger screen gives handwriting more room and makes PDF annotation easier to read. A compatible stylus can also make long sessions more comfortable than using a fingertip, particularly when I need precise diagrams or small comments.
On a phone, I see it as a convenient capture tool rather than my ideal full-time notebook. The smaller display encourages shorter notes and makes dense PDF pages harder to review. A tablet is a more natural fit for the app’s handwritten design because I can see the document and still leave space for annotations. This is not a reason to avoid the phone version; it is simply an important expectation to set before choosing it as a primary study system.
Resource use matters most when the device is already busy. If I have many demanding apps open, a long document or a large notebook may feel less comfortable than a fresh, simple page. I would close unnecessary apps before a long lecture or review session and keep the operating system updated. Those are ordinary precautions, but they make more difference to perceived responsiveness than choosing a note template for appearance.
I would also avoid using Squid as a replacement for every kind of mobile productivity. It is not the tool I would choose for a spreadsheet, a complex shared project board, or a long report that needs constant text revision. A typed notes app is more efficient for searchable paragraphs, while a PDF editor is more appropriate when the document itself must be changed. Squid earns its place when handwriting and visual markup are the main actions.
Small techniques that improve the experience
One useful technique is to create a visual language for recurring marks. For example, I can reserve one symbol for questions, another for tasks, and another for information I need to verify. The exact symbols are up to me, but consistency turns a page of handwriting into something I can scan quickly. This works particularly well for study notes and meeting records.
Another is to use layers of attention rather than trying to make every mark perfect. I first capture the idea in a quick form, then add emphasis only after I understand what matters. That prevents me from spending the first minutes of a lecture adjusting presentation instead of listening. Squid’s paper-like approach supports this because a rough mark can remain useful without looking like a finished page.
For PDF review, I recommend reading once before annotating heavily. On the first pass, I identify the document’s structure. On the second, I add comments where they will help. This avoids filling every margin and makes the final shared copy easier for someone else to follow. It is a simple workflow change, but it reveals one of the app’s strongest qualities: it supports active reading rather than passive scrolling.
Finally, I keep personal notes and shared notes visually distinct. A private page can contain shorthand, arrows, and unfinished thoughts. A page intended for a teacher, colleague, or client needs clearer writing and fewer unexplained symbols. Squid can serve both purposes, but the app cannot decide which marks are meaningful to another person. That judgment remains part of my workflow.
How it compares with familiar alternatives
Compared with a standard typed notes app, Squid feels more immediate for diagrams, handwritten formulas, page layouts, and comments positioned beside source material. A typed app wins when I need fast search, easy rewriting, or a large amount of polished text. I would use both if my work alternates between brainstorming and structured writing.
Compared with a dedicated PDF editor, Squid feels more like a notebook placed on top of the document. That is an advantage for learning, reviewing, and personal annotation. A specialist PDF tool is the better choice for precise form editing, document production, or workflows where every change must follow a formal structure.
Compared with physical paper, Squid reduces the need to carry separate notebooks and makes digital sharing more practical. Paper still has advantages: it starts instantly, has no battery concerns, and can feel more natural for some people. The decision comes down to whether I value digital organization and PDF markup enough to accept the device dependence of an app.
Who should use it, and who should skip it?
I think Squid is a strong match for students, teachers, meeting participants, visual thinkers, and anyone who regularly receives documents that need handwritten comments. It is particularly appealing if typing makes you lose your train of thought or if diagrams and spatial notes are part of your work. The free price makes experimentation straightforward, while optional purchases let committed users decide whether extra capabilities are worth paying for.
I would be more cautious if my priority is a searchable archive of typed information, real-time collaborative editing, or advanced document formatting. People who dislike writing on a screen may also find the central interaction less comfortable than a keyboard. If I mostly compose essays, maintain structured databases, or edit professional PDFs, I would choose a tool designed around those jobs instead.
The app’s broad adoption suggests that it has found a substantial audience: it has an average rating of 4.1 from around seventy thousand ratings and more than ten million installs. I treat those figures as useful context rather than a guarantee. A handwriting app can be excellent for one person and awkward for another because stylus quality, screen size, writing habits, and document needs all affect the result.
My performance verdict
Squid: Take Notes, Markup PDFs is a focused productivity app that makes the most sense when I want to write, draw, and comment directly on a digital page. Its strongest performance impression comes from short, purposeful actions: opening a note, marking a passage, sketching a plan, or recording a thought before it disappears. It feels less suited to huge archives, long typed documents, or highly formal PDF production.
Steadfast Innovation, LLC has kept the idea easy to understand, and that clarity is a real benefit. The app is free to start, rated for Everyone, and has been available since March 28, 2012, giving it a long presence in the productivity space. I would not install it expecting a universal replacement for every office or note tool. I would install it because handwriting is sometimes the fastest route from an idea to something useful.
My final recommendation is simple: try it on the device where you expect to use it most, preferably with the stylus or writing method you already own. Test a short note, an annotated PDF, and a longer page before committing to a complete paperless workflow. If those three tasks feel natural, Squid can become a dependable digital notebook. If they feel cramped or imprecise, a typed notes app or dedicated PDF editor will probably serve you better.
For me, the app succeeds not through a long list of distractions, but through a clear relationship between page and pen. I would keep it for study notes, visual planning, and document review, while using other tools for text-heavy or highly structured work. That balance is what makes Squid: Take Notes, Markup PDFs worth considering: it does one important kind of productivity unusually well, as long as I respect the situations where handwriting is an advantage and the ones where it becomes a bottleneck.
