I don't think so. Based on the screenshot from the article, I would rather use the built in timer rather than search through a bunch of pre-defined buttons for an arbitrary time.

Why aren’t iPhone users downloading it by the thousands? Because they can’t find it.

Maybe. But I think the author should seriously consider the possibility that users simply aren't interested in paying $0.99 for a timer app when the phone ships with a perfectly functional timer already.

Here's the thing about the App Store, especially as it stands in 2012. Certain app categories are massively oversaturated with too many apps offering essentially the same thing. Think flashlight apps, lock screen apps, converter apps. Even if you have an amazing app in one of these categories, you're going to have a lot of trouble making any money. I would definitely put timer apps in the same boat, especially since the phone already ships with one. If you're looking for success in the App Store you should probably turn towards a niche that has been under-filled and find a way to offer significant utility to those potential users.

That said, I do agree with the general premise of the article that App Store discovery needs to be improved.