In order to run your .IPA on Testdroid Cloud iOS devices, it must be Ad Hoc Distribution version. Follow these steps to build the correct IPA:
Make sure you have Generic iOS Device selected:
2. Click Archive from product menu:
3. Click Export.
4. Select option Ad Hoc Deployment.
5. Select your Development Team and click Choose.
6. Click Next.
Your IPA should be now compatible with iOS devices on Testdroid Cloud.