We've all seen the headlines: "Canadian man racks up $85,000 cell phone bill". "Man gets $218 trillion phone bill". "$11,000 iPhone bill for a few hours surfing".
Sometimes the digital age can be a scary place - in the 1970s, the biggest problem my grandmother had with telecommunications was finding a pencil so her arthritic hands could move the rotary dial on the big black phone affixed to the kitchen wall.
But now, the potential to trigger a financial catastrophe if just one mobile network setting is left out of place is a big reason some people still won't go near a smartphone. Even those of us who accept the risk often live in fear that checking football scores a mere metre outside of our provider's coverage area might put our children's college funds at risk.
It can be scarier than an episode of Shark Week on the Discovery Channel. More precisely, a 6.2GB high-def episode downloaded from iTunes while data roaming during a layover at Düsseldorf International Airport.
Fortunately, there's Onavo (free for now on the iPhone; Android version coming soon), a new smartphone app that can save everyone, but especially world travellers, a bundle when kilobytes count. When turned on, Onavo automatically shrinks, compresses or vacuum packs all those zeroes and ones before they are delivered to your phone from the cloud, thus reducing your data use by as much as 80 per cent.
Once you download and register the app, Onavo displays a simple interface that asks you to "Turn Savings On". It then works in the background, saving you money (perhaps a lot of money) whenever you download data via a Web browser, e-mail client or other app. Onavo then serves primarily as a meter, displaying constantly updating reports on how much data you've saved.
It can also be a handy way to measure your usage habits because it details how many megabytes you pull from different services such as iTunes or the Web.
Onavo does not yet work for phone calls, video or VoIP systems, and does not compress data coming through Wi-Fi networks.
Still, smart travellers, or indeed anyone who is at risk of downloading past their network provider's usage limits, should not hesitate to install Onavo - their future college-educated children will thank them later.
Have some great personal finance apps that you want to share? Write to Curt Brandao at email@example.com