Conjugation Drills are useful for students who want more practice conjugating verbs. It's also a good reference tool in case you're not sure how to conjugate a specific verb.
Once you have been introduced to the forms, you can hop into this tool and set up a drill with any conjugations you like.
You can either use all the conjugations, or hit Customize to practice drilling with a handful that you might be currently working on.
If you're a beginner, you might be best holding off on this tool until you've been introduced to the rules on how to conjugate the forms you'll be looking at, which is done some way into Phase One.
Once they are introduced to you, running through these every now and then will be helpful to making sure these conjugations stay in your brain.
After choosing which forms you would like to practice, you can adjust the timer and hit Begin and you'll be conjugating away.
You can also use this as a reference tool to see how to conjugate certain verbs.
Just type in the verb you want to conjugate in the box on the left here and hit Conjugate to get a nice list of everything.
So if we type, say, 食べる to eat into this, we'll get this in return:
...which is very helpful if you ever find yourself completely lost on how to conjugate a specific verb.
Do keep in mind, especially in Phase One and early Phase Two, it's more important to be able to recognize a conjugation and what it means, rather than to be able to produce it from scratch.
The quicker we're able to recognize things, the more Japanese we can get exposure to.
As we get more exposure, our ability to produce will follow.