One real issue is that most users' LaTeX environments are highly customized and tweaked to our own liking. Even if it weren't absolutely nuts to put every-package-and-extension-known-to-man inside a iOS binary, it still wouldn't be right. Like, what if I want LaTeX2HTML (I've never not had to highly tweak this)? What about my snazzy custom fonts? That bibliography style that only one journal accepts and requires these crufty old stys from 2.09?
If I needed LaTeX on a daily, here's what I would do:
1. Install DropBox on my mobile device and a designated "build" box--maybe just your home computer or an EC2 micro.
2. Set up Jenkins on a box that's got your favorite LaTeX environment and create a job that takes your LaTeX source files, builds and outputs your desired formats and pops them into an output folder you created on DropBox.
3. Set a build trigger that runs a build every time you touch a specific "ready to build" file.
4. Edit and write LaTeX source files on your mobile device using an app that syncs with DropBox like PlainText.
5. Increment something in your "build trigger" file.
6. Et voila, check the DropBox app on your mobile device for output and log files. :)
Sounds to me like a LaTeX App for iPad that offloaded page rendering to a server which also handled configuration would be a nice product. I'm guessing the market might not be large enough.
The integration is where the value is. Even LaTeX users value some kind of ease of use or they wouldn't sully themselves with LaTeX, they'd use TeX or just write PostScript directly like a true neckbeard.
Which is very similar to what I did. A simple cron job with a bash script is quite sufficient (assume a *nix environment), and you can use the make utility to add your build trigger support quite simply.
If I needed LaTeX on a daily, here's what I would do:
1. Install DropBox on my mobile device and a designated "build" box--maybe just your home computer or an EC2 micro.
2. Set up Jenkins on a box that's got your favorite LaTeX environment and create a job that takes your LaTeX source files, builds and outputs your desired formats and pops them into an output folder you created on DropBox.
3. Set a build trigger that runs a build every time you touch a specific "ready to build" file.
4. Edit and write LaTeX source files on your mobile device using an app that syncs with DropBox like PlainText.
5. Increment something in your "build trigger" file.
6. Et voila, check the DropBox app on your mobile device for output and log files. :)