To disable not only the internal browser, but also readability, please view the following:
Go into your TweetCaster settings and click on "Tweets"
Once you are in your "Tweets" settings, please remove the check mark from "Use Internal Browser".
This will then disable the "Internal Browser" within TweetCaster. From the same screen, click on "URL Action".
Set the "URL Action" to "Ask".
This will prompt you the next time you click to open any other link. Please go back out to TweetCaster, click on a link within a tweet that you wish to open/view, and click on that link at the top of your tweet options. This will direct you to the URL Options. Please do the following:
When URL Options come up, place a check mark in the "Always use the selected option":
Once you have done this, please click on "Open" at the top of the URL options:
If you have any questions or issues with this process, please contact email@example.com for further assistance.