The options is available as an advanced option for the following question types:
When this option is enabled, the users will have to answer the same question twice and both responses MUST match. A common use case could be the user email address, social security number and so on. This validation is performed on the device directly therefore it will work both online and offline reducing the chances of collecting wrong data.
Let's see it in action: on the form below we enabled the option for a "What is your email?" question
When the users answer this question they will have to enter the email address twice to proceed.
Have a look at the example project EC5 Double Entry Example.