Two smart contracts implementation for studying and testing purpose, and fully working on Remix.ethereum.org.
smart_contract.sol is a strightforward approach with just a token "ping" transaction (+1 ping, +1 token).
marketplace.sol dive into the logics of buyer, seller, price and available funds.
Since those are the first smart contracts I ever created, I took a non-trivial journey scratching at least the surface of how Solidity works, based on Solidity Documentation, YT's DAPP University and Microsoft's Reactor (by Meg Lewis!).
You can see the commented line-by-line code of those researchs in my misc repo Code Chunks: carloocchiena/code_chunks/solidity.
There I digged about the logic of time activation of smart contracts and the logic of ownership.
Proof of the works done by smart_contract.sol:
Proof of the work done by marketplace.sol:
