Uniqueness of Mobile Apps in the biosphere Apple created

    What kind of mobile apps do you most on your iOS devices? ( or any other devices? )
I use offline readers most of the time. They are Reeder, Instapaper or Read It Later.
They are good to spend time in a bus, a subway, or whenever you can read something casually.
I believe most people have the same tendency and it can be the reason those apps are so popular.

    However, they have a very interesting aspect. It is that they would not exist if there was no such popular mobile devices. On computers, they are not really necessary. Web browsers can save current web pages you are reading in certain forms. Firefox saves in a directory which resembles how the web site directory structure is. It provides options to save whole information including images, or to save text only.
Safari also allows to save in web archive. So, they literally support offline viewing capability. If there is only one which is inconvenient, it is that the saved web pages are not organized in a easy way for you to browse them conveniently.
However, if saved in a directory organized way, there is no problem.

    However, on iOS devices, the concept of "file" doesn't exist to end users' bare eyes.
To programmers, files exist. However, users would not see any individual files to open. What they see are "information". What does it mean? Try to open Instapaper or Read It Later. The cached or offline web pages are not presented as files. They are just titles on a list. Although you can think the list view as "file browser" window or view, the items on them doesn't look like "files". They are just titles of information. So, there is no way to open saved or archived files from the mobile Safari, or access those saved from desktop computers or notebook computers.
So, Instapaper, Read It Later type of programs can exist on the mobile devices.

    There could be similar apps on desktop/notebook computers, but they would not be as popular as those on mobile devices.
So, different platform with different GUI model ( not visual model, but behavioral model ) asked those new apps.

    Now, there are more interesting things.
Reeder and other RSS offline readers support Instapaper or Read It Later. Those RSS readers already supports offline reading capability. Then why do they support other offline readers like Instapapers? Is there any reason users want how they are now?

   Another interesting difference between mobile platform and traditional platform is that "what to save" is different. I still use "delicious". It is handy to bookmark at work and read it on my computer at home. If you use desktop/notebook computers which are connected always, bookmarking can be just enough. But Instapaper, Reeder, Read it later saves the whole page, not just a URL for the page.

    I think those differences are very important. When a new platform is announced, to ensure its long life, there should be reason for its existence. Somewhat blurry products may survive shortly but can die eventually. ( I think tablets like iPad can have that fate, if Apple or any other companies design their notebook computers in a way to be able to use with one-hand, can handle while people are standing, can use those in a very restricted area like airplane. )
iPhone and iPod Touch have very clear targets which don't conflict with computers. Although the both themselves conflicts each other, but they have two clear target audience. But iPad is different. It conflicts with computers. To emphasize the reason for its existence, people usually say, "iPad is for consuming info., while comptuers are to produce it.", but I don't think so. At least iPad is made like that because it is not the right time to kill computers yet. (Well, iPad is also a computer platform..anyway...) Even Apple has introduced S/W programs for creating / authoring information on iPads.
Arrr... it's off-topic.

    I think it is very important to pick the "context" for new platforms to ensure your S/W products' success. How many "context" would be still not discovered?

ADDED : BTW, I'm really satisfied with Reeder for Mac, which is still in beta. This is also interesting. Once I got used to iOS, I love to use apps influenced by the iOS on my computer. Is this the reason Lion (Mac OS X 10.7) adopted iOS features?