When your typing using the screen keyboard. The letter is put into place that you just lifted your finger off of. That is to say, the system doesn’t see you press the key, it sees you release the key.
This is important since if you press on the wrong key, you don’t have to release and backspace over it. Instead, you can just slide your finger over to the correct key and lift your finger. You will get that final letter, not the one you first pushed on.
You can use this to your advantage when you want to capitalize a letter… tap on the shift key and then without lifting your finger slide over to the letter you want and lift your finger.
Need a umlauted letter. When you choose a letter, continuing to hold you finger on it. After a few seconds a strip of optional versions of that letter will appear to choose from.