For iPhone User please try "AEI Keyboard Note" App. (This app is Free)

Original Dutch Keyboard for iPhone & iPad
* With Arrow Keys
* AEI Keyboard for iPhone (It is our own idea!)
* Easy to input “Ä ä Ë ë Ï ï Ö ö Ü ü Á á É é Í í Ó ó Ú ú È è"
* iPad Special Ten Keys like PC Ten Keys.

About AEI Keyboard
- Only One Push to input Vowel (letter).
- Less than Two Push to input Alphabet. (any letter)
- Input faster with Two Thumbs.

Useful keyboard Settings (tap"tools")
You can turn off Key Sound from it.

Please add this Keyboard from iOS Setting and switch "Allow Full Access"