If you haven't been in the job market for a while, something to know up front is that interviewing is harder, takes longer and companies are just plain pickier than ever. And this much harder interviewing process means that there is more to keep track of:
Custom Cover Letter for Every Job
Notes on Every Interaction
Scheduling Multiple Interviews
Answers to random questions for different jobs like "Why do you feel you would be a fit for this role?" or "What do you suppose are the challenges of working remotely, and how would you address them?". You're going to get questions like these a dozen or more times and while you can't always reuse them directly, if the only place you put the answers was into a web form on the job you submitted, well, they're lost forever. Store them in Job Hound and you have them for the next job application.
Job Hound manages all of these different bits of information for you and makes it all searchable too. The next job you apply for? Just re-use things as needed. And if that doesn't sell you on why you want to track everything, consider this -- a single list of all the jobs you didn't receive, in one place with all the reasons spelled out. Wouldn't having that kind of information help you figure out what you have to improve on to get the job you want?