I've just published a new app on the Android market called Coinbase Exchange (https://play.google.com/store/apps/details?id=com.black7software.coinbaseexchange).  It lets you enter multiple concurrent buy / sell orders, allows 8 different order types, notifies you when your orders have executed, and keeps a nice order history.  I basically saw the Coinbase Trader app and thought it could be improved, so I created this one.  Check it out and let me know what you think.