We used to be able to do it in the mobile app, but now you can’t. However, you can set up a routine or a virtual switch that will change to a specific mode, so that’s how most people do it.
See step five in the following
on September 15, 2016, an update was released to the android and iOS smartthings mobile apps which removed the ability to add a new mode through the app. Hopefully this was just a glitch and it will be re-added soon. Meanwhile, you can still add a new mode through the IDE. Instructions in the following thread.
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Many people use modes to manage which actions are automatically triggered. To begin with, Smartthings starts you out with a few basic modes, like Home and Away.
However, many people like to add additional modes. For example, I distinguish between Night, which is when we have a lot of lights turn on when there is motion, and Asleep, when the same movement will not turn on the ceiling lights, but will turn on a soft night li…