Thining to buy the Galaxy s6 ,but want SD support and removable battery,try the S6 Rom on your Samsung Galaxy S4 Everything is working out of the box, you also get a lot of the S6 Apps .
The latest Rom actually runs very smooth, fast and you will be able to experience s6 Apps .
Read further for more info.
Download Galaxy S6 ROM (For GT-I9500)
Download Galaxy S6 ROM (for GT-i9505, T-Mobile SGH-M919, Canadian SGH-i377M, and AT&T SGH-i337)
Please Follow the Instructions carefully and if you have any doubts ,watch the video carefully!