What application to write?

Question

Android

There is nothing to do, I want to write some kind of application that will be needed not only for me, so that I can put it on Google Play, show it to the customer if something happens. I brainstormed and realized that my fantasy in this direction is not so hot (the maximum that I came up with was to block the phone for a certain time. But in new versions of the API it is impossible or very difficult to block the hardware Home button, so I abandoned this idea). So let me, I think, I'll ask here, maybe someone has more imagination, but he can't write under Android.
Some clarifications - this should not be a game, somehow I don’t like them, the last time I played the game was 3 months ago, interest will quickly fade away. I don't want to write a server either. This should be an application for more or less the masses, preferably not one that needs root.

Answer 1

Port to native
stars.chromeexperiments.com

Answer 2

Space weather, for example. Data Sources .

Answer 3

Audio diary / reminder.

Answer 4

I really miss such a program:
application: I gave the child, for example, a cartoon from YouTube to watch (or something else) and you don’t worry about correspondence and calls, he won’t even be able to turn off or scroll this cartoon - parents will understand.
1. draw a figure on the screen with your finger and the touch and buttons are blocked, unlocking is also a figure on the screen.
2. I can offer more options, in correspondence.

Answer 5

Make an improved analogue of the "what and where" application https://play.google.com/store/apps/details?id=com....
So that instead of two entities there is one and that the interface is more convenient, so that it is convenient to navigate the tree and a search is a must.

Answer 6

On w3bsit3-dns.com there are quite voluminous topics "ideas for a programmer" and "programs to order".