I have just learnt that there is a TeX implementation now on the iPad (original source this answer to Is there a (La)TeX distribution running on iPad?). As the author of the blog post I TeX therefore iPad, this clearly warrants an update. I've downloaded the application and can confirm that it really does compile TeX documents without an internet connection (not that I disbelieved them, but some things just need confirmation). But clearly I need to experiment a bit before writing "I TeX therefore iPad: the return of the lion".
Moreover, there is a fairly big caveat: it runs plain TeX. I know almost nothing about plain TeX.
Whence a double question:
What would people like to read in a blog post? What are the features that would be of most interest (think also about the editor and environment)? (Try to make your request substantial - give some criteria to check.) What edge cases do you want testing to see if it really is TeX?
(Added in Edit) After seeing the first couple of answers below, I can provide a slightly more focussed version of the my original first question. I'm still interested in answers to the above so I'll leave it as it is, but I've also created a chat room http://chat.stackexchange.com/rooms/4598/tex-on-the-ipad for anything that is more discursive: use the chat room for things that won't stand the test of time.
The environment is an editor from which TeX is run. The format is plain TeX. It can be linked to Dropbox so I can upload files from my computer TL distribution. I can use
\input(I haven't tested if it searches any subdirectories). What files would be useful for me to upload?
How do I, a LaTeX-user, best convert to plain TeX? What resources are there for me to learn what I can and cannot do? (Apart from reading every single one of morbusg's posts.) In particular, given that it would like like I won't be able to use this for editing existing documents, what kind of document is plain TeX best suited for?