The Contacts+ dialer has T9 search capabilities.
For example, you can type the digits 523 and it'll only show the people that have 523 in their phone number. In addition, it will also show all the people with the letters J, K, or L (5) then A, B, or C (2) and then D, E, or F (3).
Note: when searching names via the dialer, accents are already included automatically when typing the corresponding digit.