Characters such as accented vowels are not shown on the Android Qwerty keyboard. However, they are available by long-pressing on certain letter keys. Accented (and other) characters are available on all vowels. Additionally, the following letters have extra characters available: S, C, N. If you need symbols, rather than letter variants, there are two ways to access available symbols.
Common punctuation marks are available via a long press of the full-stop key. More symbols, such as numbers, arithmetical symbols and further punctuation marks are available on another page of the keyboard, which is accessed by pressing the ‘?123’ button. A second page of symbols (including maths and currency symbols) can be found by tapping the ‘=\<’ button.