This app will take care of most of the planning for you. You just need to choose what sets and reps you want to do. If you want more strength but don't care about size that much, try ladders that go up to 35 repetitions. If you want to get big, try ladders that go up to 812 repetitions. And if you want endurance, go even higher!
Ladder workouts involve doing each number of reps between two numbers. So, an ascending ladder from 1 to 5 would mean that you do sets of 1,2,3,4 and 5 reps. A descending ladder from 5 to 1 means you do sets of 5,4,3,2 and 1.
There is another type of ladder, called a waving ladder, where you alternate between low and high numbers of repetitions per set. So, for a waving ladder from 1 to 5, the sets would be: 1,5,2,4,3. This is the most interesting type, as it allows you to get more work done in less time, and it will also feel almost easy.