Google Drive
One of the best things about this app is that it ties in with all other Google products. Which means Google fans can access and collaborate on all documents and spreadsheets from any browser and iOS app. It also supports several file types like Photoshop, Illustrator, and other media formats. 15GB are free, 100GB come at $5 a month, and any additional plans continue up from there. More detail on who is sharing/modifying documents is given, keeping writers in the loop of the progress of their documents. Drive is essentially the backbone of Google’s cloud-base, and the browser interface is similar to Gmail and Google Dogs to make users feel at home.
Download it Now at the Apple App Store for FREE
