iOS: Buzz Contacts replaces your iPhone's contacts app with a contacts manager and dialler that's easy to navigate, offers partial name and number search, lets you quickly SMS or call your contacts, organise your contacts by list and category, and looks good in the process.
If Buzz Contacts looks familiar, it should -- it's from the same folks who built the previously mentioned Agenda calendar app. Buzz contacts brings a minimal and easy-to-navigate interface together with some strong categorisation and filtering tools, so you only see the contacts you need at any given time, and you can quickly call or text them, start a Facetime video chat, send group messages or view their contact info. The grid layout makes it easy to browse contacts with one hand, but if you prefer the list view, it's a swipe away.
Buzz Contacts doesn't have the syncing and organisation features that an app like Smartr does, but it also doesn't need access to and permissions to every third-party service you use or every contacts source you may have. It's a good-looking, all local contacts management and dialler replacement app that makes organising and getting in touch with your contacts easy. Buzz Contacts is $0.99 in the iTunes App Store.