The correct answer to this open question is the following.
If you want to pick Abraham Lincoln, he would have used an app that could have helped him to strengthen his leadership, his command, and the operation of the members of his administration. As the great leader he was, "iCards app" would have been very useful for him.
iCard app gives you leadership and motivational quotes to have reflections that can be shared with your followers, your workers, or your teammates.