I use one of these (i've actually got a few as they don't seem to last more than a year for me)
http://www.ebay.co.uk/itm/130884616668
and the apphttps://play.google.com/store/apps/details?id=org.prowl.torque&hl=en
It does basic things like read and clear ecu codes. Also shows data from sensors and you can select what type of graph you want it on.
@[deleted] you can relocate the obd2 port just by unclippng it. Just be aware though its not really that safe to leave plugged in at all times. It is constantly receiving power and with other software people can play around with settings or worse yet duplicate a key for your car and steal it at a later point.