Dr. George Vellidis has developed an irrigation app for cotton. The SmartIrrigation Cotton App is now available. This is a smartphone app for scheduling irrigation on cotton which is available for both iOS and Android phones. You can find links to the app at https://smartirrigationapps.org/.
You can find lots of supporting information about the App if you click on Read More at the above link. Included there is a 15-minute webinar-style tutorial.