I recall hearing about Alovoa a year ago and while it sounds nice with no ads or paid features, being open source, and private data being encrypted I have to imagine the userbase is incredibly small relative to other services. Google Play lists it at over a thousand downloads but it's also available through F-Droid so that may not mean much. I have to imagine the userbase is mostly men which might prevent some users from joining or sticking around.
Either way (TL:DR) I'd be curious to see what your experiences are with open source dating apps or even apps designed around making friends.
I tried to use this app, but it seems to have a lot of users who are not interested in dating at all. There is an experimental feature called “engagement rings” that's supposed to show an indicator of who is interested, but it seems to be very unreliable.