Dude. Sentences. Please.
Firstly, I was referring to Backstep when I mentioned Safari, because he asked how to browse the TMF on an iPhone.
Now, as to your ideas... I just went to the app store and tried searching for all manner of adult keywords. Apart from blog/podcast feeds and eBooks, I got very few hits for any kind of adult material, and none along the lines of what you're suggesting. Also, as a former mobile content developer, I know that Apple's approval process is lengthy, inconsistent, and weird. For an app like the one you're suggesting to get approved, you'd need as much luck as anything else. I did suggest checking out Android instead, because AFAIK there is no rejection/approval process there.
I also want to mention that, if you're looking to locate TMFers via an iPhone app, good luck with that. This is the largest tickling forum on the Internet and very few people, women especially, fill out their location information. They don't want to be found.
So, to recap;
Is there anything stopping someone from taking the time to develop an app for tickling? No. No, there is not. Is it going to be worth the time? Very, very doubtful. Feel free to give it a go.