I'm amazed what this app can do with a tiny 1.4 MB (the size it occupied on my Nexus 5) what other Apps achieve with many times that size. I'm equally impressed by its accuracy: I compared with a brand name App over five days and found it to be just as accurate. And lest I forget  it's also very frugal in consumption of the battery. Kudos to the developer for all these achievements.
December 10 2015