With DropBox I can access all of my files from all devices, including my iPhone and iPad. You can’t do much with files from your iPhone but you can actually do quite a bit from the iPad, including saving files to DropBox folders
I also use DropBox as part of my backup solution. I don’t save files anywhere but DropBox, meaning they are automatically backed up to both my desktop and laptop. I pay $10/month for 1 TB of space so for that price my files are stored in 3 places and always available. I have Crashplan but am going to cancel it because if I ever needed the files, the restore process looks painfully complicated. .
I also pay $2/mo for 100 GB Google Storage so my photos are backed up there as well.
DropBox is wonderful for sharing files with team members, contractors, anybody, including the pubic. Just drop the files in the Public folder and send someone the link.
DropBox rocks! You get a certain amount of free storage space when you sign up (2 GB?), then you can earn more (up to 18 GB I think, or it might even be 32GB) by referring people. I already pay for 1 TB but hey you can never be too rich, too thin, or have too much DropBox storage space. So signup for DropBox today and let’s both get some free storage space!