There are various digital applications on the market to achieve the exact tuning of each string.
For Windows and Android:
Tune!it which you can download from the following website: http://www.tune-it.com.au/
and gStrings Tuner: https://play.google.com/store/apps/details?id=org.cohortor.gstrings&hl=en
For iPad and iPhone: (find in the Apple Store or iTunes)
Tuner by plusadd: https://itunes.apple.com/us/app/tuner-by-plusadd-chromatic/id635644097?mt=8