The Night mode feature works as usual, dimming your device's screen so it doesn't strain your eyes when viewed in the dark. The data-savings page lets you see and adjust how much data you're able to shave off your time spent browsing – the traffic exhausted could be shrunk down to to as little as 10% of its original size. Private mode offers private tabs that don't save any information when they are closed.
Opera Mini is free and available from Opera's mobile page.
source: Opera Software