Packt Publishing publish mainly technical books. They have a "Web App" that you can access (need to register) through https://app.packtpub.com/ . It lets you read ebooks from their library in desktop and mobile browsers. Everyday there is a free ebook you can claim. Or you can buy other ebooks for $5 each. I am not sure if this includes every title in their library, but it seems so from a cursory check.
The daily free ebook can vary a bit. Today's title is "Microsoft Windows Identity Foundation Cookbook". In the last few days they had: "jQuery UI Themes Beginner's Guide", "MySQL 5.1 Plugin Development", and "Elgg 1.8 Social Networking".
Note 1: With the daily free ones you claim, it seems you can only download them to your browser's local storage. You can't download in the proper ebook formats like epub, mobi, pdf. With the $5 ones you buy, you should be able to.
Note 2: The Web App works fine with Google Chrome. But on my Android phone, download and page turn don't work. Hopefully they will improve it.