Tried it on my Galaxy S3, worked OK for about 14 days, ssving around a quarter of data using email and other apps, then phone became unresponsive regularly and wouldn't connect, to network and wi-fi also it got very hot and the battery ran out quickly. Rebooting will fix it for a day or so before the faults come back. After 10 or reboots I uninstalled Opera Max. The phone works OK now. Good app but needs much improvement. An off button would be useful so it can be turned off when using wi-fi for long periods or using phone in aeroplane mode.