The Cross Slide is an old lockscreen theme for MIUI that has been now optimized to work with all screen resolutions including 720p devices like the Galaxy S3 and HTC One X. It is a very simple yet elegant theme with date, time, calls and message, and charging information. The author of the theme is not known.
The theme has been tested on my SGS3 with MIUI V4, but it should work with MIUI GB ROMs too. The original version of the theme was in Chinese so it has been translated into English before being posted. Enjoy!