Happn is a dating app, in which you have to turn on your gps and have to walk, or to do your daily routine or simply while travelling. And it will show profiles of that people which you had crossed paths with.
I used this app for one week, and I only able to get 2-3 profiles. On downloading this app they gave 5 free credit from that you can send a "Hi" . But after then you can only click like, and when that person will like back you are able to chat.
That's is fine with me, but the bigger problem is you will get less profiles, because its very hard to cross paths with happn users.
Where as if you will compare this with Tinder, in tinder they will give all the suggestions as per city or town or even neighbouring states. So you have more chance here of talking to someone.
Verdict - You can try with app, but will get bored of it, as you will not able to find anyone. So better why to waste time and data, don't download.