The Daily App: Box.net

The free Box.net service allows for simple upload, download and file-sharing of files across the Web and mobile apps, as well as 5 GB of storage and the ability to upload files of as much as 25 MB. If you choose to pay $9.99 per month, you get 25 GB of storage and the ability to upload files of 1 GB each.

A business version for up to 50 users goes for $15 per month per user and gets a total of 500 GB of shared storage and 2 GB file sizes; it also provides a greater number of third-party "add-on" apps that integrate with the Box.net on the Web.

After a recent upgrade and redesign, Box.net allows for creation of documents right in the Web app -- a la Google Docs -- and their integration with mobile apps. (Although in the mobile app, we found the Web Doc text so tiny in the iPhone's Retina display that it was difficult to make out.)

The Box.net mobile app is free.

This is a service that has proven itself to be reliable, scalable and valuable over several years, since its first launch, and its extension to mobile apps is a natural.