The data usage application monitors how much is being spent and the extended standby mode increases the standby time up to 4 times.

ENGADGET: Sony reveals 3.5-inch Xperia E single or dual-SIM Android phone, coming early next year

Xperia ZL also includes Battery STAMINA Mode that significantly improves the battery standby time by automatically shutting down battery-draining apps whenever the screen is off and starting them up again when the screen is back on.

ENGADGET: Sony Xperia ZL goes on pre-order for US customers, off-contract: $720 for HSPA, $760 for LTE