iDrive offers Android users its Mobile 100GB Cloud Storage Plan (50GB backup + 50GB sync) for 99 cents per year. (Download the app for Android for free.) That's tied with our April mention by far the most affordable mobile backup annual plan we've seen; for further comparison, Google offers a similar service for $1.99 per month or $23.88 per year. This service includes multiple device support, real time backup, file sharing, 256-bit encryption, and activity reports.