I have an idea I've been toying with for a dating tool (I refuse to call it an app) based on the premise that all dating "apps" and "sites" are horrible because their incentives are aligned toward wanting people to actually use them. You pretty much have ad-driven and subscription models and both have perverse incentives. Further, the whole "wink", "like" and "swipe" nonsense increases the "meat market" commoditization and dehumanization of the whole thing.

So my idea is to put all the incentives the other way. The tool is designed to operate on a budget of ~$0. I would accept donations, but otherwise have no monetization and therefore no desire to increase "engagement" of any kind. My incentive is such that I actually don't want you to interact with the tool, because that will cost me bandwidth and processing time. I will allow you to have a profile of text and one single image of restricted size, because I don't want to have to host anything else. You will fill out a multiple choice questionnaire with as few questions as I feel I can get away with to ensure at least some level of basic compatibility, and then you do nothing.

Periodically, a cron job will run and see if anyone matches, then it will send you both each others profiles (through good old-fashion email) and ask if you'd like to go on a date. If you've both agreed, there will be a sequence of messages from the system proposing date ideas, locations, and times until consensus is reached. Then it's all up to you. This is designed to ensure that you make a real human connection to the person in a real life interaction before any contact information is ever exchanged.

It probably sounds as though this sort of thing would have a hard time attracting users. I consider that a feature, because it means it'll cost less to run and it will avoid attracting ego-inflation seekers, low effort numbers gamers, and other ungenuine people.

As envisioned, I would expect this sort of thing could cover a moderately sized state on a raspberry pi.