In the latest version of the Qntrl Android mobile app (v2.0.5), we have brought in support for Lookup and Relation fields within the app. Now you can choose options from Lookup and Relation fields while adding/editing a card and also in performing transitions.

Look Up fields in 'Add Card' form :

An example of a look up field:

 Card Detail view:

In 'During' transition form:

Relational Cards List in Card Details 'Related' Tab:

Please update the app either from the Play Store or using the link given below:

Qntrl mobile app - Play Store

Do try out the feature and share your feedback in the comments section!