Hi, new to the forum and not sure if this is the place to ask related question, if not please point me to right direction.
Is this possible that we write a smart contract which does a transaction? Like one party selling something and other is buying, now there is a bit trust issue as who will transfer first. Is this possible that smart contract acts a middle man and once both transfer money and goods/ services to etehreum than there transfer them to respective parties?
If yes will I need to pay some fee like transaction fee to ethereum?
If I want to develop a mobile app which speaks to smart contracts how can I do that? do we have some apis or sdks for that?