Here's how I make pictures like this with it:
Step 1: Building blocks
Start by framing your first shot at one side of the area you want to cover. Let's say you want to work from left to right across a landscape scene. Take your first shot. Make a note of a key item in the picture. Move your phone camera across to the right a little way to take in some more of the scene. It should look a little different -- but not too different, so make sure you include the same key item in it. You are aiming to give the app plenty of overlap to work on. Continue the process, changing your key items as you go. Sharp, clear edges work best as places where joins will work well.
I've shown my "key items" in the seven separate pictures here by adding image notes for you to read: