Most user application need some sort of display and user interaction through buttons and a touchpanel.

Many possibilities, varying on the requirements:

Something we all use during the day: remote controls are everywhere: media devices, domotics and security appliances.

So far, we have built up some considerable amount of experience using low power setups in IR and RF approaches.

An overview of recent custom developments in this field:

Looking for some output power, high sound quality and maximum efficiency? D-Class is the answer.

Along with a high quality volume control chip, this makes a great amp.

The Microchip dsPIC33F series has become our standard workhorse

Mp3 decoding ranges from using VLSI chip VS1053 and the latest VS1063 along with a FAT32 filesystem on a micro SDHC card, up to the use of a dedicated USB-host chip like the Rohm BU9458

A good quality FM tuner chip is hard to find nowadays!

Previous used chips for portable applications include TDA7021, TEA5768, Si4731. These are not well for suited high-end solutions.