The IFTTT maker channel is a good alternative for any IBeacon receiving station app that can send an HTTP request. Then just have it turn on or off a virtual presence switch in SmartThings and you should be all set.
Or you could have the ibeacon app send the request directly to a smartthings Web services smart app, but that’s going to be more work to set up.
The BeaconSandwich FAQ has a good description of how IFTTT can be used with their app. The process would be the same for any other app that allows for writing http posts.
And I know you probably already have one, but just for people who don’t, here’s a SmartThings virtual device type for a virtual presence sensor which can be turned on and off as a switch and so works well with IFTTT.