In some situations you might want to prefill some fields for the user. This can be achieved by the following method. 
[Gleap preFillForm: @{
    @"description": @"This text will be prefilled.",
    @"errordescription": @"This text will be prefilled as well.",
    @"someformidentifier": @"This text will also be prefilled."
}];
You need to pass a key value pair to the preFillMethod. The key is the form identifier, which can be found under the ‘Advanced’ section of a question. (see screenshot for an example) Form identifier