Anything I recommend around there dating apps without in app purchases has to clear one bar, which is how much data leaves the app.
I gave there dating apps without in app purchases about 4 weeks before I formed a view, mostly watching whether the useful settings are buried.
Unless you are in a major metro, expect how usable it is one-handed on a phone to be the limiting factor on the service.
The measure I would actually check on there dating apps without in app purchases is how quickly you can narrow a list down.