Within a month, the coalition has doubled the number of its members.
Notable names include app makers Epic Games, Deezer, Basecamp, Tile, and Spotify – some of which have previously been involved in public battles with Apple and Google over App Store subscription and in-app charges.
According to the CAF, both companies have been involved in anti-competitive behaviour.
The CAF has been critical about payment charges and commissions as high as 30%.
In addition, Apple has been criticised for restricting iOS app developers to its own App Store.
The new partners include smaller developers like Beonex and Imagine BC and app makers such as Breath Ball and Eristica, but also interest groups like the Mobile Marketing Association.
Eristica, for example, previously stated its outrage over Apple shutting down its seven-year-old social app business that allowed users to raise funds for charity.
The app maker said it followed through making all the changes Apple demanded but still couldn’t get its app back onto the App Store.
Passbase said: “Apple has repeatedly denied the submission of our App due to weird and inconsistent rules. We’ve been denied based on reasons that they applied to us, but other competitors were allowed.”