I've got a number of deployments around with various dell kit, a nice M1000e, with a mix of M610 and M710 and M910, more recent servers such as R730's and R630's most sites have 3024 or 3048 stacked switches, so having 24x7 eyes on the hardware via OMM has been great.
Recently not so much though due to what I first thought was issues with ios9, so I've just let it be and hope apple pull their finger out, but now after iOS10 and a new phone and still no I've looked in to this further, and I've found that it looks like the app just doesn't seem to work on the Apple devices any more.
Just for the record,
1) all my OME servers are now patched upto v2.2.0.1
2) all OME servers can be accessed via the webpage in the web browser
3) all OME servers can be setup and access via Android devices,
4) all OME servers can be accessed via safari on the ios devices (though obviously displays install Silverlight prompt!)
I'm only posting this to see if anyone at Dell can confirm (or deny) if there is any kind of issue with the iOS platform and OMM and if any other users are finding the same issues?