Apps should support multiple accounts

Apps that are backed by some kind of service in the cloud should support multiple accounts. This is a no-brainer but several apps fail to provide this convenience feature. I’m particularly frustrated by the Kindle app. Though it could apply to other apps like Netflix.

Why would you need multiple accounts. Well, you might have a personal account and a business account, for starters. You may have an account you share with other family members, and so on. It is of course quite likely that limiting the number of simultaneous accounts to two or some such upper limit is desirable, for performance reasons and to prevent abuse.

Apps that cache

I am fed up with having to track which apps cache data without my consent. Here’s a list of iOS apps that cache relentlessly and don’t give me an option to clear the cache. It is easy to know which apps are caching by looking at their storage space usage in settings.

Amazon Cloud Player

As it streams and plays music online this app caches music offline. I have deleted it several times in frustration. Luckily, it is not an app I frequently use.


Dropbox will silently cache files you access, whether you favorite them or not. According to its official documentation, it caches content offline when you favorite it. In practice that is not what it does. A workaround to clear the cache is to log out from your account and log in again. I use Dropbox a lot for storing my e-books, a pity I cannot just delete the app and be done with it.


This app probably shouldn’t be on this list, but beware if you have some older version of it. A while back I even adopted Pulse out of frustration. I am back to being a frequent user since they resolved the problem.

Storage space being a premium on mobile devices, caching should be very carefully designed. Otherwise, you may rob someone from taking that spur of the moment photo or something else equally useful.

There may be other apps you know of, comment below. I’ll evaluate and add them to the list above.

Medium and information

I have been thinking about medium and information lately. Everything around us can be distilled into these two broad categories. Medium represents something physical, having characteristics derived from the material, but whose reason for existence is to sustain information. Though due to the fact that it exists, medium assumes a life of its own.

Information is the abstract, the software, shall we say, supported by the medium. It is in information that we find the codes required to create, sustain or destroy the medium.

The living organism

We all know the medium that carries genetic information, the DNA (or RNA in simpler organisms). DNA itself is part of the complex processes that lead to creation and sustenance of life.

Learnt behavior in animals

At a more visible level is the information stored in the brains of animals. Information that is received through all the senses. This includes complex rituals in humans of writing and reading, besides several others.

Machines and the digital computer

Artificial machines and the digital computer are similarly mediums that store information. In varying manners they all somehow act on that information resulting in some behavior.

Their relationship

Like the yin and yang, chicken and the egg, it is a thoroughly philosophical exercise to discuss what came first, what is more important. The medium has no meaning without information, which cannot exist without the medium.

We have been able to extract information from some media and transpose to other, such as text from paper to the magnetic disc, but the essence remains the same. Maybe that is a distinguishing characteristic of information, it can survive in different media, lifeless, requiring an external agent to interpret it. An agent that can assimilate information and change. Maybe we are that, maybe along the path to that, a perfect combination of both.

Stretching that thought a lot further. Is the entire universe such an agent? Maybe at some level, like mass and energy, media is information, and information is all that is!

Here’s a parting thought…

Anton Zeilinger in his paper A Foundational Principle for Quantum Mechanics

DIV with scroll

This is a continuation post to Avoiding HTML5 Canvas.

If, instead of panning and scrolling the entire browser window, you want to pan or scroll the image inside the DIV, replace lines 18-19 as follows.

      $('body').css('overflow', 'hidden');
      imagediv.css('overflow', 'scroll');
      imagediv.width($(window).width() - 10);
      imagediv.height($(window).height() - 10);
      imagediv.append($('<img src="' + url + '"/>'));

I have subtracted some pixels from the width and height of the DIV so that it fits snugly inside the browser window, without the need for scrollbars to pan the DIV itself. A more accurate measure of the scrollbar width can be used instead.

On Safari for iPhone with iOS 6, the height restriction on the DIV has no effect, it is automatically set to the image height by the browser. The width restrictions works all right. On the iPad, and other browsers, the DIV appears snugly within the browser window and the image can be panned using touch-and-drag. I did note the pan to be slightly sluggish, indicating an implementation that is not hardware accelerated.

Pinch to zoom does not work inside the DIV, although the entire document window can be pinched to zoom. I have heard of, but not experimented with, implementations such as iScroll 4 that provide this capability. With hardware acceleration lacking, performance may not be all that good.