A number of years ago, Working Assets (a "socially conscious" mutual fund) started to provide long distance service. That service morphed into Credo - I'm not sure if they spun out the business or sold it, but the transition was seamless from the customer point of view. Later, Credo started to provide wireless service as Credo Mobile.
As far as I know, Working Assets itself went out of business a few years ago, when the CEO (?) became ill, and needed to retire. They found another "socially conscious" fund to take over the assets (the Working Assets mutual funds were terminated, with the money going into similar funds managed by the other organization).
For what it is worth, I have been a satisfied Credo customer for years, but have not tried Credo Mobile.