Make the text bigger if it is hard to read. It changes right away.
Prefer writing by hand? Most phone keyboards can switch to handwriting. This is a phone setting, not part of the app. On Android (Gboard), add the Handwriting layout in the keyboard's Settings → Languages. The SayIt main page also has a pad for writing with your finger.
If you hear nothing, check that the phone volume is up. Saved phrases stay on this phone only. They are not sent anywhere.
Send to another phone Packs your saved phrases into a single link. Text that link and the phrases open on the other phone. Nothing is uploaded to a server — it all lives inside the link.