I would use the first click testing for my mobile app. I found that this would be the most useful given the type of product an app is. First click also has a high completion rate compared to the sorting test (91% for the first click and 81% for the sorting) and is more relevant, given that users wouldnā€™t need to navigate so many tabs. It would provide more of a ā€œwhere would they first go to look for this particular page/itemā€ so that I would be able to tell if an icon or tab needs to get moved or changed. Given the median time of 1 minute 35 seconds, I would also be able to conduct more tests per day/session vs the other two, potentially allowing me to get more data about how users are using the app. A good example question/task would be ā€œfind your user profile pageā€ and then I could see if they clicked on the home icon, I would then be able to change either the layout or icon presentation to better convey the idea that ā€œthis is the home page and this is your user pageā€. Given that this is an app meant to reduce the amount of time a pilot has to spend on the ground, it would also be helpful to know exactly how long they spent on each screen of the app, if I found that one page is often needing more time than the others, I could better optimize that page so that the information they want can more quickly be found.