It took me a while to learn the details. Here's my understanding of it.

Recognizing of BT-LE devices is left to the app and not the phone or OS (as long as it supports BT-LE). One has to go into the app to scan for and connect the device.

You need to search for apps that support BT-LE devices and those seem to be in short supply. ipbike has a beta version for Android + BT-LE.

For some reason the market seems to have no interest in producing BT (not LE) monitors--even though it can be used with all legacy/current/future Android phones. Short battery life cannot be the only reason--think of all the devices we charge regularly, starting with phones, laptops, ....

To use Android phones (w/o built-in ANT+ chip) as a bike computer as of today, buy a ANT+ USB dongle (make sure that your phone supports USB host mode, i.e., USB on-the-go cable--Moto G seems to be the least expensive one). This is the route I am taking.

Feel free to correct/update/critique what I said.