The tiles for the Osmo Words game are only available in English. We do not have any additional letters or accents used in other languages, such as 'é', 'ç', 'ñ', or 'æ,' etc. That said, we do hope to make these available to customers in the future.
However, you can use accented letters when you create your custom album (corresponding non-accented letter tiles will be recognized by the game as equivalents of the accented letters).
Please use the "All Languages" dropdown menu on the album search page to see some examples: