We are grateful to Nigel Deacon, a UK enthusiast of red and pink-fleshed apples for the following details:
From the noted California plant breeder Albert Etter in 1944. Bright pink flesh; light pink blossoms. The fruit is crisp with a sweet/tart flavor, conical shape; skin is a creamy pale green. Parent is red-fleshed Surprise. This apple was the Etter Surprise hybrid singled out for patenting and official introduction in the mid 1940s. Good flavour but is very tart for a dessert apple; almost a cooker.
More details on Nigel's website.