The half life of a smartphone is around eighteen months.
If a Smartphone's half life is around 18 months (full life would then be about 3 years) and then considering the cost for a new one at every three years, seems to me that electronic versions of the Bible don't last as long as a hard copy.
I gave up paper Bibles a couple of years ago.
And then when you have a power failure, or you Mobile device goes on the blink, lost it, or it got run over by a big truck, then you don't have a Bible.
So, when I look at these things I reckon it would be wise to keep your hard copy of the Bible. The bottom line is that you still have one.
For me, there is nothing that actually beats picking up your (paper) Bible, opening it up and begin reading it. Software Bibles are good but you're tied to a machine in order to read it. Take a Bible with you for a walk, and you don't have to worry about you mobile device's battery going flat on you. If you go hiking, camping, or something like that, the hard copy of the Bible just doesn't crap out on you. Moreover, nothing beats the feel of a hard copy of the Bible.
Blessings,