Decentralized applications on Ethereum, also called dApps, which are enabled by smart-contracts leave room for innovation and the possibility of rethinking. This article presents some dApps and show the application potential of decentralized applications on the Ethereum blockchain.Most of these dApps require the installation of an Ethereum client or the use of MetaMask, a lightweight Ether wallet, as a Google Chrome extension.ETH Notifier ETH Notifier is an application with the simplest concept: to allow the sending of SMS via the blockchain of Ethereum.This dApp allows the automation of sending SMS with a 100% availability rate that only a blockchain can allow. In addition, ETH Notifier supports encryption of the target phone number so it can not be made public on the blockchain. The service will work in conjunction with IPFS to allow the storage of the message in a decentralized and secure way, while ensuring its availability.In the ‘beta’ phase on Ethereum’s main network, the service should ultimately allow sending SMS from a web page, without having to create a smart-contract. It should also be able to be used in connection with other dSPs, such as an external service. The service is under development (support for Mist and Metamask planned).Etherisc Etherisc is a dApp that shows the effectiveness of the Ethereum blockchain on an interesting use case: to allow the creation of decentralized, automatic, and above all transparent insurance.The use case put in place by the Etherisc team is that of flight delays. The principle is simple: We pay a ‘fair premium’ (a sum similar to an insurance for a concert ticket) and if a delay is found on the flight we automatically get compensation. We can obviously adapt this to many areas! The contract works in a completely decentralized way and the verification of the data is done by a call to an oracle (in this case Oraclize).Currently deployed on the Ethereum test network, the potential of this dApp has also been rewarded: the startup Etherisc recently won the “Blockchain Startup Contest”.Proof of Physical AddressDeveloped by ConsenSys, Proof of Physical Address allows (as its title suggests) to create a physical address proof.Just fill out a form, pay a registration fee (0.57 ETH), receive a username and enter this identifier on the dApp. So we are registered on the Ethereum blockchain for 365 days. Why ? Our address is proven, and when calling the function “hasPhysicalAddress (your Ethereum address)”, it returns the value TRUE.We imagine the different areas of applications and the simplifications that this could allow when registering on different sites requesting a physical address check (online banks, exchange platform, etc.).In practice, this project is a simple version (Minimum Viable Product) of much larger projects launched around the management of decentralized identity on the blockchain. These include the uPort project, still by ConsenSys, which aims to enable everyone to manage their digital identity in a decentralized way.EtherDeltaWhat about the creation of a decentralized exchange platform? This use case is an Arl├ęsienne of decentralized applications; both the exchange platform is a weak point of blockchains, regularly hacked.EtherDelta is the answer to this request, allowing the exchange of ethers and / against different tokens, in a completely decentralized way.If EtherDelta is not yet seen as the substitute for large exchange platforms, such as Poloniex or Kraken, its decentralized and fully transparent operation has something to seduce. It proposes a first approach to a market that operates automatically and transparently, without outside intervention.WeiFund If the purpose of WeiFund is the same as a crowdfunding platform, that is to say, the crowdfunding of a project, the means are quite different: the management is obviously decentralized.The fees are much lower than those of a usual crowdfunding platform, and many campaign templates are available. All you have to do is modify them, define the counterparts, and everything is then part of the blockchain in the form of smart-contracts: clear, stable and transparent.The use of these different concepts and smart-contracts related to the possibilities of evolutions and associations between them, make glimpse a spectacular field of application of the blockchain technology and especially of Ethereum and its Turing-complete language. Ultimately, the synergies enabled by the platform will allow these applications to operate using these different services in new use cases. For example, EtherDelta could meet kYC obligations using uPort, etc.