I have an idea for an android app and I'm interested if it is legal.
Basically there are sites where people upload their recipes for vape juices, and all of these recipes fall under this specific licence.
What I'm trying to do is to create an app that collects all of these recipes. Sort of an archive, and it would also have a calculator for quick mixing. Later on I would add possibility of user creating accounts and adding new recipes etc.
My question is, is this legal if I give the appropriate credits to each recipe? And could I put adverts on the app or would this fall under commercial use? Also what if some functions of the app would cost money(this would not hide any recipes behind this "paywall") such as users adding new recipes?