Apple has stunned the wider development community with an emailed announcement that it has decided to slash commissions for App Store affiliates from 7 percent to 2.5 percent, starting May 1. The cuts apply to all apps and in-app content, Apple said. However, they do not apply to commissions for movies, music, books and TV, which will remain at 7 percent. The company will continue to pay commissions on Apple Music memberships as well. Both the extent of the cuts and the brief notice provided — they go into effect next week — are surprising.