How about we start this conversation with ownCloud? " ownCloud gives you universal access to your files through a web interface or WebDAV. It also provides a platform to easily view & sync your contacts, calendars and bookmarks across all your devices and enables basic editing right on the web. Installation has minimal server requirements, doesn’t need special permissions and is quick. ownCloud is extendable via a simple but powerful API for applications and plugins. "
You have access ownCloud app from the Google Play store at the cost of 0.99$
This is one of the major opensource players for creating your own cloud service running on your own box from your home. It's fully compliant with Windows, Mac, Linux thus allowing the freedom of working with which ever platform you want.
I highly recommend watching ownCloud's video
My next highlight is Transporter Sync from Filtransporter at the cost of 99$ but that's only for the Sync device, with this you need your own storage device but it will enable all your device to be able to connect to it and sync up. The setup is easy and fast. Connect your USB device to the Transporter Sync, connect the device to your network and voilà done, you have access to the data on all your devices.
" Transporter Sync turns any external USB drive into your own private cloud. Featuring all the same sync, access, share and protect functionality of the Transporter in a compact form-factor starting at just $99 with no monthly fees. "
You can also find the required app on the Google Play store.
There's currently a Kickstarter project which features a really solid, hardcore, awesome system by Lee Allen called the moxibox which you can check out right here : Kickstarter Project - moxibox
The last alternative that I have for you guys is to buy a system that already is built for CloudService such as a LacieCloud, D-Link share center or even Western Digital 4TB Cloud Share anywhere system which will allow you to access your files from anywhere.
Now the last method involves spending a bit of money to setup the system but in the end you know it's guaranteed to work. But if your up to it the first method is a DYI and should be pretty forward. If you Google the services, the apps and the different systems I'm sure you will be able to find something that will work for you.
Mind you if your looking for an all online solution this isn't it, you'll have to make sure it's working and maintained and if for any reason a drive fails then you'll loose data and or if you haven't planned for redundancy then your in for some pain.