I have a lot of experience with EmberJS and I will try to debug you application. Please consider that the version of EmberJS could cause the errors as it's a known issue in some versions.
How I will proceed:
1. Days 1 and 2 - inspect application and try to apply some hot-fixes and test its stability on an iPad
2. Day 3 - if needed an upgrade to the framework will be applied, otherwise, continue doing day 1 and 2 if necessary
3. Day 4 (if needed) - recheck all the application behavior on iDevices, Android as well as desktop devices if needed.
4. Day 5 (if needed) - sum up the work done and present a report to you.