@gec78 Are you using an iPhone 5 or above? If not the app is not recommended (I've got an iPhone 4s). Go to Adobe Shape CC – Capture and create vector shapes on the App Store on iTunes and click on 'More' under the description. It states:
Adobe Shape was developed for iPad 3 and iPhone 5 or newer models. Not recommended for older models and some features may not be available.
My understanding is that it has limited functionality on iPhone 4/4s.
Hope that helps. Probably not worth upgrading to iPhone 5 just for the app!