Now OneFeed has a tag cloud, more responsive UI across desktop and phone browsers. Also performance of this site is improved a bit.
Tag Cloud
Both Javascript and CSS can implement tag cloud. A JQuery plugin called jQCloud can produce very beautiful tag cloud. But considering Javascript may be disabled, a CSS implementation is more reliable. My implementation is largely based on this CSS tag cloud.
Responsive UI
First of first to implement a responsive UI,
<meta name="viewport" content="width=device-width, initial-scale=1.0">
For others like @media query and relative width, this doc from Google is helpful.
Performance Tuning
Most ORM frameworks like JPA and ActiveRecord have N+1 queries problem, because they fetch associations lazily.
The tag strings on the index page of OneFeed was loaded lazily when the ERB file was rendering,
which caused a typical N+1 queries problem.
Rails provides includes method to eagerly load associations, which reduces queries to 2 times.