Hi,
first, thanks for a great app, I use it daily.
My suggestion would be to not "destroy" the last word suggested if the user presses more keys. For instance you can type a word, but you need an ending on it, then if it's only one word left as a suggestion, add the letters on the key pressed last.
Example: I want to use the english word "destroyer" but bend it in Swedish to "Destroyern" (the destroyer). Everything works fine up until destroyer and I press the "6" key (I use T9 layout). The suggestion goes from "destroyer" to "Ddptpmwdpm", instead it could be suggested as "Destroyerm" "destroyern" "Destroyero". It's easy for the user to then just tap and select the correct word and get it added to the dictionary. As it is now I need to choose the last word, select it, press a key again and select a single letter.
This is my only big issue with the app itself. That I sometimes can't spell to save my life is another story...