Dropbox has been a life saver in both my classroom and outside.
Anyone who has been or will be in a 1:1 teaching environment will need to master workflow -- how you're going to deliver items to students, how will they return it, how you will grade it, and how you will return it to them. Fortunately for me, my school has an enterprise version of Schoology. Thus, I use that for my typical workflow.
Dropbox has become essential to me because I need to access my material from numerous devices. At any given time, I will be using my personal laptop, the desktop computer in my classroom, my iPad, or my iPhone. With my material in Dropbox, I might even use your computer at your house.
Professional purposes are very obvious. Beginning my first 1:1 classroom last year, I needed to convert anything I wanted to use or create into a pdf. Past practice would have compelled me to save the files on the school district server, but I wanted easier, 24/7 access. Dropbox is the simple replacement.
Dropbox is excellent for students because it allows them to save something from their iPad and access it later from a computer at their house. I often had my students backup their work into Dropbox. For delivery, I used Schoology and Livebinder. The students wrote on assignments or activities I posted in Notability. From Notability, my students saved the final product to their Dropbox folders. At the end of the semester, some of my students left my 1:1 section. By putting all of their work in Dropbox, they had access to it even without their iPad.
Dropbox allows you to create shared folders. This is why many teachers have decided to use Dropbox as their workflow. The teacher creates a shared folder with each of their individual students. I stayed away from that because I thought there would be too much clicking (and found Schoology to probably have the same amount). I prefer to use Dropbox as a backup to Schoology. Every once in a while a student would have trouble delivering something to me for a variety of reasons. A shared folder in Dropbox is a simple sollution.
Dropbox gives you 2GB of space for free. However, a great perk is that they give you 500MB everytime you get someone to sign up. I'm up to 7.5GB!
I also use Dropbox for my basketball practice plans. I have a shared folder with my assistant coach. This is akin to team teaching. I like to create the practice plan and put it in the shared folder in the morning of an afternoon practice. This helped our communication. My assistant coach can look at the plan any time through the day and see what drills he might be leading that day. He can be organized and add suggestions. Once this season, I had an emergency and couldn't make it to practice. The plan was already in Dropbox. I didn't need to do anything more, and my assistant could access it right from his phone.
Dropbox has personal uses as well. Nothing says romance like a shared Dropbox folder with your wife. We have shared pictures. But also, we are currently renting two properties -- both from before we were married. Managing them can be cumbersome. All of the documentation goes into the shared Dropbox folder. This way, if one of us is talking to the tenant or a contractor, we've got everything we need.
Dropbox was especially a life saver when we made our offer on our current house. This is a great house, and we needed to move fast. No time to get to our own computer and printer/fax machine. We were at my wife's parent's house when our realtor emailed over all of the documentation. I needed a place to quickly store documentation, print, sign, scan, save, and return to the realtor. I did this all with my iPhone, Dropbox app, and my in-laws printer/scanner.
Speaking of in-laws, I even have a shared Dropbox folder with my mother in-law (insert your own joke here!). I needed to record a live song with my iPhone and get her a copy. The file was way too big to email. The shared folder in Dropbox was just way to easy.
As you can see, these practical personal and professional uses make Dropbox an essential resource.