Calgary Herald, by Dan Healing.  A six-month-old app developed to track and identify drilling rigs in Western Canada has been burning up the rankings for free business downloads lately.  And the nine staff at Calgary-based startup software developer PetroFeed Inc. couldn’t be happier.  “It’s gotten some exposure and things are working out pretty well for us,” said founder and chief executive Ashley Dunfield. “We’ve gotten crazy explosive growth in the ’patch.” OPINION: The burden of proof that SB21 is the right plan for Alaska is on the oil industry now, [...]