Throwing dating apps out to the board because search results on it are useless.
First message inside a day, or the safest free stops mattering because they've moved on. For the safest free dating apps, keep socials private until the conversation has run a few days.
If the safest free dating feels like work, the filters are probably wrong rather than the app. The the safest free thing nobody mentions is how much timezone and schedule overlap matters.
Public place and own transport — same rules for the safest free dating as anything else.
Anyone selling certainty about the safest free dating is selling something.
Grindr
Scruff
Jack'd
Hornet