... with the help of ES Explorer and a Google Play-enabled device.
Google Play can be a pain to install on Mele (and other Google non-supported devices), and if you don't need to have your Mele device in sync with your Google account, there is a simple way to install simple applications.
ES Explorer has a very useful tool: the App Manager. It allows you to send from an Android device (with Google Play) to another Android device (without Google Play) an application package provided that each one has launched ES Explorer and both are connected to a local network.
The main drawback is that the installed applications are no more connected to your Google account (no update notification, no Google account support)
Here is a step-by-step howto, to install Mount Manager app on the Mele device without having Google Play installed.
I took my Android phone, and installed Mount Manager.
On the Mele device, simply launch ES Explorer.
On the Android phone, in ES Explorer, go to Tools->App Manager: