Robust app I've been using this app since 2012 and was one of the first apps I installed when I got this new phone. However has been a bit disappointing recently. Minimising stopped back up. And if it stopped at 15/100  haha! No chance it would let you back up the other 85 items. Still better than the other apps out there. Just waiting for bug fix. No other app backs up whatsapp. Also  it works just fine as long as you don't use auto back up.
May 14 2015