Despite this, let me share with you a very interesting trick I learnt from the article "Getting the Most Out of QR Codes Using URI Schemes".
Essentially, think about the mailto URL which allows the browser to open the systems' default mail client. It seems such non-http URI schemes can be done for mobile phones allowing you to scan a QRcode to open your smartphone native apps to carry out an action. Somewhat similar to mailto: is tel:
It seems if your mobile browser opens say tel:
Unfortunately if you put such non-html strings into most qrcode readers it won't work. To get around this problem you shorten tel:
How about using url shorteners like bit.ly or goo.gl that both shorten the url and generate qrcodes? Unfortunately both seem to fail to accept such URI schemes. The QRCode below when scanned via QRcode reader will call my office number on your phone.
Even more interesting the same method works for many apps as they register URI schemes when installed.