If you have difficulty holding two keys down simultaneously, you can activate Sticky Keys in iOS 9 and 10. Sticky Keys allows you to access keyboard shortcuts without having to hold multiple keys down at the same time. To enable Sticky Keys, go into your device's Settings app. Go to General, then Accessibility. Tap Keyboard, then Sticky Keys. Toggle Sticky Keys to ON.
Below you will find a table of hotkeys that you can use with Proloquo4Text and iOS.
Hotkeys for Proloquo4Text 1.2 and later: