I got mod-approval for a lighthearted mini-plot, and it is open to any character (whether they're in the country or not) who would download apps for their phone.
In between the meetings she's had, Violet got bored and made a game app called Cosmic Competition. It is very addictive (think on the level of Candy Crush & Pokemon Go). Although the app itself is free to download, there are paid add-ons, and like Candy Crush, there's a half hour time out that you can pay to bypass/get new "lives" and continue playing. The game can be played individually, or you can compete against other users if you know their username.
There's even a muggle friendly version of the game - the only noticeable difference is a few special effects in the magical one that don't exist in the muggle friendly one.
Aside from being able to bypass the time out, paid add ons include the ability to customize your star sprite character and buy equipment for the sprite that lasts for 30 minutes that makes it easier to get to the next level. 50% of all proceeds go to charity. Publicly, the app is listed as being produced by a company called New Horizons, and the app information states that the charitable proceeds will go to families in need.
Please feel free to have characters get absurdly competitive over high scores and such. There is a leaderboard that has been programmed to update every four hours.