Ehm sorry but talking about "full control of our own data" in a paper written with Microsoft Word and presenting a mobile app is like talking about peace while empty a magazine aiming at someone else body.

Beside that to have our data, witch does not means privacy, does only means owning A COPY of our data in a fully locally usable form, we need home storage, desktops, home offline copies etc. We need to state a thing: to be Citizens in the digital world, as we need a home in the physical one we need a digital home that's OURS not rent from someone else. Witch means today having a home server for sharing purposes, with a static ip, enough upload, a domain name (or at least a subdomain) and so on.

WE CAN'T OWN anything on a mobile simply because the platform is managed/manageable from remote NOT under our control. We can't own anything on proprietary tools or services.

The dream have a name: classic internet. Witch means a network of interconnected hosts, where one of them is ours, down to the hw. A world of desktop computing where we both produce and consume, sharing between peers, the cloud at maximum reduced to "scalable cache/computing resources in the Plan 9 alike model" and so on. The rest is just marketing.