What can't you find online these days? Check out Steep.it, a site that can help brew a perfect cup of tea everytime.
It's pretty simple, just follow the brewing times recommended in their chart, and enter the one you need in the timer box at the top.
Once you've input your time, the site is the timer for you and it goes off when it's time to remove the teabag or loose tea leaves.
Also check out their sister site e.ggtimer.com for, you guessed it, timing eggs and more.