Apps that put Amazon Alexa on your phone aren't as good as they could be

As someone who recently bought--and was quickly enchanted by--Amazon's Echo connected speaker, I've been thinking of ways to get its Alexa virtual assistant into more rooms of the house. Of course, I could just buy another Echo speaker, or some other Alexa-infused device such as the Echo Dot, Amazon Tap, or Invoxia's Triby. But what if I could just use my smartphone to access Alexa instead? Or better yet, what if I could repurpose an old smartphone to act like an Echo full-time? Such is the promise of a couple new smartphone apps that have Amazon's Alexa assistant built-in.