Has anyone ever seen this fruit for sale in US fruit markets - in particular, Philly area?

I've never seen it, but you made me google it and here is another pic and a description:
Rollinia

Sounds like it is strictly tropical.

-Krista

It looks a lot like a fruit that grows in the Bahamas--the name is something like amendola, but that's not quite it (the name, I mean)

jan

I've seen Chirimoya (custard apple) for sale in Asian and Spanish markets here in Seattle. I looked the fruit at Frieda's, a special fruit/vegetable provider. They have a listing for Atemoya which they say is not available in the US. Another relative is Soursop or Guanabana. These are all in the same family.

I've only seen Chirimoya for sale. On one website said Rollina/Ririba spoils quickly so it may not be something that can be transported.

You may want to look for a chirimoya for a similar fruit.

Custard apple is delicious; lots of black hard seeds though; It has a fleshy texture but this pommy didn't think it is like custard.
To eat it you just break it apart and eat with your fingers or a spoon, spitting out the seeds. You don't cut it like the picture shows, the picture is for illustration only.

We had a tree in our garden in Brisbane, and we have put in a tree in our new garden here.

If it is a Rollinia then it looks very similar to the custard apple. I haven't tried rollinia.