Sometimes the toolbox can disappear.
To bring it back, rotate your device to portrait mode. Then, the toolbox should reappear.
If this does not work then you should offload and reinstall the app. This deletes the app but preserves the data and puts a "fresh" copy of iAnnotate on your iPad/iPhone. We've found this often resolves issues that develop between iOS and iAnnotate.
To do this, start by going to your settings --> general --> iPad (or iPhone) storage --> scroll to iAnnotate and tap on it --> tap "Offload App" --> Restart the iPad --> Reinstall the app.
