FontSwap [Cydia]

FontSwap is the program that can change the style of the text in the entire system. Want to change the font in a lock screen - no problem.

It has recently been updated to version 1.5. New version fixes some bugs and adds some small new features. First you will have the opportunity to fully restore the original system fonts through a convenient button "Restore Default Fonts." Also the alignment bug is resolved.

You can find FontSwap in Cydia (repository BigBoss).