This is not about just up-scaling an app. Tablets are a completely different form factor which means that from a UX perspective, one needs to think different and create an entirely new UI.
Have a look at different iPhone apps with iPad variants. Oftentimes the iPad version embraces the additional space to offer more or more detailed or very different functionality.
The comparisons in question list apps that have specifically been created with this in mind. Apps for Honeycomb that rethought the Phone UI and adapted it to fit the constraints and new possibilities of a tablet.
Since, after all, Tablets aren't just blown-up smartphones.
What the author of the article implies is that just recompiling a smartphone app for the tablet form factor should count as porting. That's akin to Apple saying they have 100.000 (or what) iPhone 4 apps because people updated the background graphics for the retina display. That would certainly be true, they're still iPhone apps though.
Thus, just changing some parameters so that font sizes are corrected doesn't make a smartphone app be a tablet app. The form factor is different.
This is the very misunderstanding that is being discussed.
Android's UI system does support tablets by 'upscaling'... but the API has been improved (with Fragments amongst other things) to provide flexibility to design one UI* that works well on any size of device.
I'm sure they felt it was necessary to do it that way because of the fact that you can get an Android device with just about any common screen resolution these days.
Sure, some people will be lazy, and won't bother to make their UI take advantage of all that space. But a lot of iPad apps (especially early ones) weren't exactly high quality either. But lazy developers are an issue on all platforms.
*One UI that might include components and layouts that only show up when viewing it on a phone, or a tablet, or a whatever.
Are there guidelines around this? If so, how many levels do they specify? I imagine a 4" screen is "small" and a 10" screen is "large", but what's a 5" or a 7"?
The comparisons in question list apps that have specifically been created with this in mind. Apps for Honeycomb that rethought the Phone UI and adapted it to fit the constraints and new possibilities of a tablet.
Since, after all, Tablets aren't just blown-up smartphones.
What the author of the article implies is that just recompiling a smartphone app for the tablet form factor should count as porting. That's akin to Apple saying they have 100.000 (or what) iPhone 4 apps because people updated the background graphics for the retina display. That would certainly be true, they're still iPhone apps though.
Thus, just changing some parameters so that font sizes are corrected doesn't make a smartphone app be a tablet app. The form factor is different.