Xcode: No Scheme

Close Xcode and delete the folder <username>.xcuserdatad from within <projectname>.xcodeproj/xcuserdata/. Then restart Xcode, the schemes should re-appear.

EDIT: You may need to delete from .xcodeproj file and .xcworkspace file

I think this is happening when you are opening the app.xcworkspace not app.xcodeproj.

Solution: Install the pod and open the app.xcworkspace again.

This worked for me

1. Click on No Scheme
2. Click on Manage Scheme
3. Click on Autocreate Schemes Now