Use APKPure App
Get Random Letter Picker old version APK for Android
This app with pick a random letter, optionally speaking it out loud.
This app with pick a random letter, optionally speaking it out loud. It can also provide a countdown timer after the letter is shown. I wrote it for use with the board game ASAP, but I'm told it works for Scattergories, too.
It can also roll a six-sided die.