Need expandable text box

Proloquo2Go is invaluable to me, as I am a Disability Rights Advocate and Public Speaker and use your app to deliver my speeches.
The one comment I would like to suggest is to make the text box (the one where the user types in their message) expandable. I use a word processor app to type my speech, then I copy and paste it into Proloquo2Go.
The issue is once I listen to my speech (before I deliver it), should it need editing, I am forced to go back to the word processing app, edit it there, then copy and paste it once again in Proloquo2Go. I may repeat this process a few times, until I get my speech the way I want it.
If the said text box was expandable and vertically scrollable, as many text boxes are on websites, I could do my edits there instead of having to switch back and forth between apps. Depending on the length of my speech, I could possibly type the speech directly into Proloquo2Go.
I understand that the way that your app currently is, I could edit my speech directly if I used an external keyboard which has left and right arrow buttons, however I normally use an iPad to type my data, and an external keyboard is usually not available. An external keyboard is also an additional cost which many individuals with disabilities cannot afford, thus reworking your text box to make it expandable and vertically scrollable would be the solution to this issue.

Ms. Cali B about Proloquo2Go AAC, v4.3