Hey there !
Had no idea what Joiplay was until 30 seconds ago but I still can answer some questions !
Yep, this is a Ren'py game. An Android build is not (yet ?) available tho, as it will recquire lot of extra work.
I got a lot of requests for an android build, so I promise to look into it as soon as I can. Finishing chapter 2 still is my priority anyway. :)