One such app is KeyNote, which comes free on the IPad.
One problem with GoodNotes and Metamoji Notes is that it can be hard to layer the items used to decorate the planner. If you decide you want to move an item, and it is layered on top of something else, using the lasso to move it will move everything it touches, and that can be frustrating.
With KeyNote, you can build your layout outside of GoodNotes or Metamoji Notes, then copy and paste the entire layout to GoodNotes or Metamoji. It does take a little effort, but those who have chosen to do this feel that the extra time and effort is worth it. Some find it easier to resize objects on KeyNote as well.
Although there are some additional apps I use in creating layouts, I have not yet learned the ins and outs of KeyNote. I have not had a problem using GoodNotes. One of these days my curiosity will get the better of me and I'll spend an afternoon sorting it all out. But if you are familiar with the app, and you want to do some things you might not be able to do within GoodNotes, you might want to give it a try. This app may make a huge difference in your digital planning experience.
I will defer to my fellow digital planners Lavonna Mae Bakke and Lisa Marie Hart who have both done videos on creating layouts in KeyNote.