Trembling text on iPhone

I've never experienced that kind of issue before.However, here you have two solutions.

Solution #1

Adding the following to the css should prevent the font from resizing.

html {  -webkit-text-size-adjust:none;}

Since it seems to only be an issue on iPhone it would make sense to target only that terminal with media queries:

@media only screen and (max-device-width: 960px) {   html {     -webkit-text-size-adjust:none;   }}

Instead of applying this to html you could add it to #breadcrumb, .post-meta and other selectors that has the same resizing issue.

Solution #2

The issue also seems to be related to the following ruleset:

a,.textwidget a img,div.category a,.sociable ul li {  -webkit-transition: all .3s ease;  -khtml-transition: all .3s ease;  -moz-transition: all .3s ease;  -ms-transition: all .3s ease;  -o-transition: all .3s ease;  transition: all .3s ease;}

changing that into:

@media only screen and (max-device-width: 960px) {   a,  .textwidget a img,  div.category a,  .sociable ul li {    -webkit-transition: none;    transition: none;  }}

will also solve the issue.

In your case I would have chosen solution #2, since solution #1 shrinks the text size of the targeted elements.