Unbeknownst to most of the crypto-enthusiasts, one of the most interesting features of the recently implemented Lightning network is one of the least discussed: the ability to create decentralized apps (known as the Lightning Network or LAppps apps) on top of the Lightning Network mainnet.
But Bitcoin is not complete and does not have smart contracts?
It does not matter. Because of the brilliant off-chain implementations through the Lightning network, the moment has arrived when the Bitcoin blockchain supports "decentralized apps", this is mainly due to the innate infrastructure of multi-sign and off-line transactions through the channels of payment of LN .
A payment channel is a bidirectional and out-of-chain connection between exactly two nodes (users / parts) that allows very fast transactions (hence the name). Once both nodes, or users, close the channel, the final balance is extracted and all that is added to the Bitcoin blockchain is a single transaction with two signatures.
A single node, however, may have more than these two channels channels open at any time. Moreover, the logic can be introduced on top of a single node, making known said node to host the payment channel to create a type of service or automatic game. An image below shows all the LN nodes from Thursday 13 September at 17:08:
Overview on LApps  The fact that the Lightning Network ("LApps") apps are now available on the Bitcoin blockchain address two common points of discussion. First of all, it is no small secret that the lack of "decentralized apps" within the Bitcoin ecosystem is one of the, if not the strongest, critiques of Bitcoin.
Indeed, in many cases, it is the single motif Ethereum, Lisk, Cardano and a plethora of blockchain platforms exist in the first place: to create and offer an intelligent contract based on blockchain and a decentralized app environment . All of a sudden, Bitcoin stands silently, but literally approaches the supposedly bigger competitive advantage.
What does this mean for Bitcoin? Massive incoming adoption on multiple fronts: incoming blockchain developers, current Bitcoin hodlers and probably other platform blockchain veterans. At some point in the not-so-distant future, it is an unlikely but perhaps possible scenario that most of the current contracting and intelligent engineers abandon the current blockchain of choice for the most solid of all. Only time will tell it; however, for now, no obvious development community has moved sides.
In addition, another major advantage of LApps is that, being built on the lightning network, they are inherently structured for micro-transactions. Microtransactions drastically lower the barrier to entry; which once again consolidates the idea that LApp will see a large influx of users and developers in the near future.
The current use cases for end users in the Bitcoin world are, well, quite limited to financial activities; financing / management of portfolios and exchanges. LN not only broadens this variety, but makes a double hit focusing on experiences at affordable prices.
The real question about adaptability at the end will, by habit, spring from actual engineering production: how many LApps are in production?
Despite its relatively recent origins, a large number of LApps have already been publicly distributed; All released LApps can be found in the official Lightning App Directory. Blockstream, the Bitcoin consulting giant with a significant amount of Bitcoin Core developers, has been publicly published in support of LApps. In the second half of March, Blockstream organized a "Week of LApps" event dedicated exclusively to the development and dissemination of LApps. Only this intermittent development event involved the activation of seven LApps, some of which are illustrated below. A qualitative and rudimentary classification of public LApps, together with some related demonstration summaries, can be as follows:
Point-of-Sale & Vendor LApps
Accepting payments with Bitcoin is a breeze for e-commerce platforms or custom web applications – however, high commissions and unpredictable confirmation periods have previously been accepted by accepting Bitcoin an evangelical business decision at best. With the LApp exploiting the Lightning network, suddenly the two biggest objections to the adoption of Bitcoin by an online business are dissipated. It follows that the point of sale and supplier apps have become the main stage while the LApps are beginning to develop:
- Nanopos – A simple point of sale system for fixed price goods
- WooCommerce Lightning Gateway – A complete application of e -commerce that integrates with the stock management and order tracking systems
Content Creator LApps
A common use case for additional blockchains and additional tokens is the publication, management and licensing of original digital content. How many are in this category? You do not need to look too far to find a blockchain / token for posting blog posts, tracking music metadata or managing illustrations. Theoretically, any original multimedia content probably has a decentralized (or failed) app. Surely the LApps unlock almost frictionless payments with the biggest cryptocurrency of all – but without a standard form of digital tokenization, is there the same level of traceability of resources incorrigible for the content that creates LApp?
Here are some examples of web content creation apps created on the mainnet lightning network:
This third category of LApps represents experimental LApps that are primarily examples of existing technologies with enabled lightning payments. Recall that the Lightning network does not necessarily allow decentralization as much as it allows for frictionless Bitcoin payments – which certainly unlocks a vast amount of previously economically unfeasible use cases to be tested. 
- Lightning Jukebox – A fun demo that reinvents a classic technology for Lightning Network
- Nanotip – The simple jar tip, rebuilt to issue bills Lightning Network
As seen above, a handful of minimally feasible LApp are now live in more cases of use. The LApp ecosystem, while it is now publicly in use, is certainly still in its early stages – this does not detract from the extraordinary breakthrough for Bitcoin which is the Lightning network. Other blockchain platforms have beaten Bitcoin to punch (in particular the EthCeum ERC20 ecosystem), we are likely to see developers create popular cat-copy LApps – perhaps an equivalent CryptoKitties? Or a forecast market to compete with Augur?
In order to achieve the above examples, much work is needed. For now, there is no off-line LN solution for the tokenisation of standards such as ERC20 or NEO5. Without digitizing resources using tokens (forget about ICOs), can LApps really compete directly with decentralized apps?
Currently, two of LN's many implementations are seeing most of LApp's activities. First of all, Eclair, which is a Scala implementation of the Lightning network created by ACINQ. Eclair hosts four LApps including the Eclair desktop app. Secondly, it is the most popular LN implementation C-Lightning, which is, as its name suggests, a "C" implementation. The C-Lightning LApps are based on the C implementation of the Lightning network and are part of the Elements Project.
As you can see in any explorer, the Lightning network is no longer in its theoretical or even alphas-stage: it is a successful Bitcoin solution, growing exponentially, out of chain. Unfortunately, there is no tool within the Lightning ecosystem that tracks the adoption of specific LApp nodes within the main Lightning Network network; but I'm sure someone is working on it while I finish this article, the LN ecosystem, after all, is evolving at the speeds of lightning .
A colleague of mine asked the question "why build solidly on the Ethereum virtual machine while a regular Web stack with Ubuntu hosting a Lightning Network LApp node can offer a competitive, perhaps even better, user experience for the 39; end-user? "While I remain neutral in LApps and dapps directly competing until the LN ecosystem accounts for resource tokenization, the second half of this quote highlights what developers should keep in mind when both ecosystems mature.
The early and late majority of decentralized app users will not care if their transactions are off-chain, off-chain, multi-verse confirmed, hash with Musk1024 or anything else – they simply want more UX experience fluid enabled with this alleged blockchain thing that uses magic digital money and without friction.