Back in December of last year, I wrote a review of TexPad for OS X and I was seriously impressed with it. I gave the app a solid 9/10 as it made typing TeX on a Mac simple, easy and pain-free. Now the developers, Valetta Ventures, have released an iPad version and they very kindly provided me with a promotional code for the purpose of this review.

TeX on an iPad, you say? Well, there are barmier things that have been written for it. Let’s have a look at the iPad version of TexPad and see if it fares up to its Mac counterpart.

## What is TeX?

I presume that if you are reading this review then you’ll have some knowledge about what TeX is. But for the people who don’t, let me just take a minute to explain precisely what it is.

TeX is a typesetting system that was invented and developed by a guy called Donald Knuth, who was a computer scientist at Stanford University back in the 1970s. It’s a typesetting system which uses a set of simple commands and functions to render text, and it is widely used in the world of academia and science mostly because of the way it renders math and mathematical equations. Knuth’s idea was to create simple-looking standardised documents that would look the same as time passed.

An example of a short document programmed in TeX, with the document parameters set at the top and the content below.

Learning TeX isn’t hard at all (you could learn the basics in a couple of days), and it is a very flexible system for typesetting. I use it extensively for my university studies (as do my lecturers), as it allows you to forget about formatting — all your documents are presented very neatly when rendered.

## Features

So, enough about TeX now, let’s have a look at TexPad and what it’s like to use. When you open it up for the first time, you’re greeted with the welcome screen, which will ask you where you want to store your TeX files. TexPad can either store them locally on your iPad or you can link it up with Dropbox, so they’ll be synced across any device you use.

From here you can also change the encoding used, the font used in TexPad for displaying your code on screen (you’ve got the choice between four) and its size. To create a new TeX file, you need to select the folder you want it stored in (I’m going to create one in my Dropbox folder) then you’re ready to go. TexPad will create a new TeX document with the document class (i.e. the type of document – this affects how the document is rendered) as {article}. It’ll also create the \begin{document} and \end{document} tags as well (everything in your document goes between these two tags).

Typing TeX on TexPad is a real joy. The default iPad keyboard gets a few extra keys, such as easy access to the \ % \$ { } [ and ] keys. All of these operators are used extensively within TeX and having them there so you can tap on them quickly is a really useful feature.

Typing TeX on TexPad is really easy thanks to the auto-complete command function.

All commands in TeX are preceded by a backslash, and the moment you type this on TexPad, a little menu pops up with an alphabetical list of all TeX commands. Once you start typing the first couple of letters of a command, TexPad will find it and you can simply tap on the command to insert it. This really does save a lot of time in the long run.

TexPad can also flag up errors whilst rendering, although it doesn’t highlight the error in your code (it just displays it in the log) — a feature I would have liked to have seen (and one that would be extremely useful, especially for beginners).

Errors in your document are flagged up whilst rendering.

In the above screenshot, I deliberately typed

\begin{Title

without entering the final } at the end. TexPad did flag up the error and defined it as {Title, allowing beginners to find out where they went wrong, however it would have been nice to see it highlighted in the code.

When you “render” your document (or typeset in TeX-speak), TexPad takes all that complicated-looking code and transforms it into a nice looking document. Typesetting in TexPad is either done locally (i.e. on your iPad) which creates a DVI file that can then be viewed directly from the app or (if you’ve linked up Dropbox) via the cloud. If you typeset via the cloud, then TexPad creates a PDF file which is then saved into the same folder/location as your original .tex file. So, the following code (for a really simple document):

 \documentclass[11pt,fleqn]{article} \begin{document} \title{Welcome to TeX} \author{James Cull} \maketitle \begin{abstract} This is the abstract to this document. \end{abstract} \section{Introduction} This is the introduction to your document. \end{document} 

yields the following when typeset via the cloud (Dropbox):

I personally find that the local and cloud typesetting, although a very useful addition, is more intended to give you a guideline on how your document looks rather than the final point of reference for your document. Given the cloud sync, you can open documents created on TexPad using any TeX editor, however, you can also create documents solely on the move as well. It’s up to you as the user.

## Final Thoughts

The release of TexPad for the iPad does, in my opinion, mark a shift in attitude of the iPad. TeX is a very specialized typesetting language, only really used in the world of science and academia, and the fact you can now use your iPad to type it on the go really is really something very interesting. The iPad has shrugged off the days of being basically a glorified slate that you could play games, browse the web and tweet from, and has become something of a specialist piece of kit in some fields.

At the start of this review, I asked whether TexPad lived up to its Mac counterpart. The answer is, without a shadow of a doubt, yes. It retains almost an identical set of features (including error logging and auto-completion) and is by far the best way to type TeX on your iPad, despite other options out there in the App Store. I personally prefer to create my documents on my Mac, as I prefer the use of a physical keyboard; however, TexPad does make it really easy to type TeX on the go and it thoroughly deserves its 9 out of 10 rating.

## Summary

A full-functioned TeX editor and typesetter for the iPad.

9