Getting values of text displayed on the screen of Android device

I have a project that is concerned with gathering all the common words used on mobile devices. Is it technically feasible to collect all the text that is being displayed on the screen o开发者_JS百科f Android device? Even for System screens and applications screens.

You can search through all the system applications and retrieve the content in the string files - https://android.googlesource.com/.
There is no way for you to screen scrape arbitrary applications on a standard, production firmware Android device: probably be a major security violation.