I need to create an android app to receive contactless payment from my clients. how can I start that? My clients will be phisicaly in the shop with theirs cards like master, visa, so on, and my selling android app I have, I wish to implement a Soft Pos to receive that payments when the clientes put theirs cards under my mobile phone.
I do not know if I have to contract some service first to develop that or if you could give me some tips and web sites where I can start I really appreciate it.
Regards.