iOS Citrix Receiver 7.2 released on the 24th of March now calls on several new services. One in particular is https://stream.launchdarkly.com:443 which we have observed opening a bi directional session over icap and not dropping (some connections were over 20 hours). Our proxy struggled to facilitate all the sessions with some devices opening up to 10+ connections. Note we are using Bluecoats as our explicit proxy.
We have raised to Citrix and will update this forum with any outcomes. We have blocked this address and not seen any impact.