Never spend a minute doing a task that you can spend the rest of your life automating.
When you have one thing, you need one hand. When you have two things, you need two hands. When you have three things, you need a database.
I created a turn by turn navigation app which is now available on the Windows Phone store for WP8 devices. I was unsatisfied with either the quality the existing apps or the price, so I went ahead and created one of my own. It simply provides voice navigation with the minimum necessary effort on your part. If you have been unhappy with the turn by turn navigation situation on Windows Phone 8, like I have, then this is the app for you!
It’s ok for two threads to modify the same value at the same time, so long as both values are correct.