HomeVault is a cloud storage service you can easily host at home. The server part works on any platform that supports PHP and MySQL. The apps offer file storage, automatic photo backup and more coming soon.
If you're looking for the client apps, the server includes a web based one, acessible at the default HTTP port and you can use the same address in the HomeVault Android app and the HomeVault iOS app.
To get started with HomeVault, you simply need to get a PHP server and an empty MySQL database running. Afterwards just copy the HomeVault Server content from this repository to the default HTTP directory, load the server address in your browser and follow the simple steps shown on screen. After logging into the administrator account you can add more users from the top right user menu.
Luckily all of that is much easier to do than it sounds.
Platforms with an available snapshot (the HomeVault snapshot eliminates the need for any setup and just runs the server on localhost):
After installing the server successfully, you need to enable port forwarding to the default HTTP port on your router. You can learn how to do that here. Unless your IP is static (most aren't) using a dynamic DNS service is recommended for your own comfort. One of the most popular free services that offer that is No-IP.
Developers can take advantage of HomeVault's open API which can easily be integrated into any app. All of the currently available functions are documented in the mobile_methods folder. You simply need to provide the username and password (and other optional arguments) as a POST request, as described in the linked file.
HomeVault administrators can also feel free to modify the server however they want - as an open source piece of software, modifications are encouraged. One of the simplest mods would be changing the background throughout the web app by simply replacing the image in res/drawables/homevault_default_backdrop.jpg.