Ever get frustrated that you can’t zoom pages on a mobile device (e.g., Facebook)? Here’s a bookmarklet/favelet that’ll re-enable zoom on any web site.
Then, when you go to a page you want to ‘Zoom’, just click the ‘Zoom’ bookmark and that page will be zoomable.
1. Make a bookmark
(you need to edit something, so it doesn’t matter which bookmark)
2. Change it’s name to ‘Zoom’
3. Replace URL of this bookmark with JavaScript Code
Now, just delete the URL address of the webpage you initially bookmarked (http://www.qz.com/… in the above screenshot) and replace it with the following JavaScript snippet.
javascript:document.querySelector(‘meta%5Bname=viewport%5D’).setAttribute(‘content’,’width=device-width,initial-scale=1.0,maximum-scale=10.0,user-scalable=1′);
Tap Done on the keyboard, then Done once again in Bookmarks to finish the process.
Source: How to Re-Enable Zoom for Websites That Block It in Safari for Your iPhone « iOS Gadget Hacks