Google account holders and non-holders can be set to access and/or collaborate on files/folders in real-time. Additionally, you can find files you've shared not only by filename but by person you've shared the files with.
You can use Dropbox via website, by installing a desktop client that creates a folder that you simply drag and drop files into, or with their mobile app. Everything synchronizes across all devices used and cloud storage. Dropbox also offers easy methods of sharing whatever is within it.
The initial FREE allocation is 2Gb which sounds like a lot, but you run out of that space quickly. The next level up is 1Tb @ US$99/year. So if you think 10Gb might do, you have to opt for the 1Tb option.