ANU #5 — App Store Foundation SDK, Wallet and GDC

AppCoins News Update, or ANU for short, is a regular bi-weekly update by the AppCoins team. As usual we are going to cover dev updates, market reports, team members and upcoming events. This week’s focus is on ASF SDK implementing the In-App Billing, ASF Wallet, AppCoins IAB smart contract and AppCoins attendance at the GDC and TOKEN2049 events. You may expect the next ANU on March 28th.

**Quicklinks**Dev UpdateAPPC Markets ReportFeatured Team MemberUpcoming Events

The last couple of weeks have been spent working on the products we’ve set to deliver by the 21st of March:

• ASF SDK implementing the In-App Billing (IAB) process for the AppCoins protocol
• ASF Wallet with the IAB flow integrated
• AppCoins IAB smart contract performing the revenue split and storing data in the blockchain when an in-app item is bought
• App with the ASF SDK integrated to showcase the AppCoins IAB flow

ASF SDK (alpha version)

We’ve been working in an SDK to be delivered as part of the App Store Foundation (ASF) work. The SDK will be delivered by the 21st of March as an alpha version and implements the IAB flow of the AppCoins protocol.

By integrating the SDK in their Android apps, developers will be able to allow users to pay for in-app items using APPC tokens. Upon integration, developers can specify the SKUs present in the app, as well as their ETH address that is supposed to receive payments for the items bought by users. We plan that the integration of the SDK should take no more than 10 minutes for a developer already familiarised with the Google Play IAB process.

The SDK is constructed in a way that integrates seamlessly with an AppCoins compliant wallet. Such wallet is able to process the payment intent issued by the SDK, perform the transaction and report back to the SDK with the respective result. The first AppCoins compliant wallet will be delivered by the ASF.

ASF Wallet

We’ve been working in the ASF wallet for some weeks already, and we’ve already published the alpha version in Google Play and in Aptoide in time for the MWC demo we were doing. If the reader wishes to be up-to-date with the most recent developments (may be unstable), they can be found here.

Since then, we’ve been implementing the functionalities needed to accommodate the AppCoins IAB process. For that, the wallet needs to be able to recognise a payment intent launched by the ASF SDK, process it and perform the transaction, and send the result of the transaction back to the SDK.

Regarding the recognition of the payment intent, both the SDK and the wallet are implementing the EIP681, which creates a standard to represent transactions and allow cross-application communication. An example of a URI created by the SDK representing a transaction using APPC tokens is the following:

ethereum:0xab949343E6C369C6B17C7ae302c1dEbD4B7B61c3@3/transfer?uint256=1000000000000000000&address=0x4fbcc5ce88493c3d9903701c143af65f54481119&data=0x636f6d2e63656e61732e70726f64756374

The wallet recognises the intent and parses it, knowing that the URI is encoding a transaction composed by a call to the method transfer implemented in a smart contract in the address 0xab949343E6C369C6B17C7ae302c1dEbD4B7B61c3 (APPC test token contract) in the test network 3, which is the Ropsten network, with 3 arguments: the amount of APPC to transfer (already in wei), the address to send them to, and the data to be passed.

With this information, the wallet then calls the approve method of the APPC token smart contract stating that the AppCoins IAB smart contract (detailed below) can spend a certain amount of APPC tokens in behalf of the user. The amount of APPC tokens is set to the price of the in-app item the user wants to buy. The reason for this call is related with the fact that the revenue split of the payment and the actual transactions are done by the IAB smart contract and not by the wallet. One may argue that the wallet could compute the revenue split and then perform the transactions itself but we intended that this logic would be implemented in the blockchain, with all the data stored there for posterior validation, if needed.

After the approve call finished, the wallet then calls the buy method of the IAB smart contract. After the payment is done, the wallet sends feedback to the SDK regarding the result of the transaction.

AppCoins IAB smart contract

This smart contract implements the revenue split, which states that 85% of a purchase goes to the developer, 10% goes to the app store that installed the app and 5% to the OEM that pre-loaded the app store in its devices. It also stores information in the blockchain about the purchase in the form of an event. The reader can see the smart contract here.

It has one main method that verifies if the contract can spend the needed amount of APPC tokens on behalf of the user and if so, performs the transactions to the developer, the app store and the OEM with the respective amounts of APPC tokens by calling the transferFrom of the APPC token smart contract.

It also sends an event in order to store all the relevant data related with the purchase in the blockchain for posterior validation by the developer or anyone interested in doing so.

App with the ASF SDK integrated

In order to showcase the AppCoins IAB process, we decided to integrate the SDK in Trivial Drive, an open source game that is used to demonstrate Google Play IAB. It will allow us to present the easiness of the AppCoins IAB flow, as well as show how easy it is to integrate the SDK in an app and how it interacts with the ASF wallet.

The version of Trivial Drive with the SDK integrated will also be published in our repo as an example to developers that want to integrate the SDK. There will also be documentation about the steps needed for the integration.

Next steps

After the release of the above artefacts on the 21st of March, we will focus on the Advertising use case of the AppCoins protocol. This use case is the one where developers can create advertising campaigns that reward users depending on the attention they give to the apps associated with the campaigns.

The Advertising use case will also be composed by several artefacts, such as the upgraded ASF SDK and Wallet, and smart contracts implementing the necessary protocol logic that needs to be in the blockchain.

Feel free to follow our work in our several Github repos: ethereumj, contracts and wallet.

The current market cap is close to $38.39 Million USD, with $2.38 Million in volume in the last 24 hours across these exchanges: Binance (42.80%) and Huobi (57.20 %).

APPC value continues to be tied to Bitcoin. BTC has recently experienced currency depreciation due to several factors. One of the reasons was due to rumors regarding the apparent irregularities in popular exchanges. Another reason was the fact that regulatory bodies, such as the US Securities and Exchange Commissions (SEC) and Japan’s Financial Services Agency (FSA), have recently taken new enforcement actions to increase regulatory measures on all platforms that operate as exchanges. Although the recent announcement may have led to a decrease regarding BTC value, and consequentially other virtual tokens, including APPC, in the long run, appropriate regulation of exchanges will result in greater security measures for all customers. You can see more info about APPC markets at Coinmarketcap.

Name: Carolina MarçaloRole: Head of PartnershipsBio: Leading the B2B Partnerships in Aptoide App Store for the past 4+ years, Carolina Marçalo, one of the co-authors of AppCoins white paper, is currently working with partners to adopt AppCoins Protocol and leading all relations with the crypto-exchanges.

AppCoins will take part in the world’s largest professional game industry event: The Game Developers Conference.

What once started off as a gathering in a small living room has now developed into a week-long conference, complete with hundreds of lectures, tutorials and round-table discussions on game development and virtual reality topics. The event expects over 26,000 industry experts and enthusiasts.

Be sure to check the AppCoins meeting room (NDA Room 6 — #310 (South Hall Level 3)) and have a chat with the AppCoins team, on Thursday, March 22nd, to learn about the several benefits regarding the AppCoins protocol adoption, including: increased revenue share, decrease risk of fraudulent traffic and, one single APK integration that works within all AppCoins-enable App Stores.

We will also have a Speaking Session on Wednesday, March 21st in Room 2011,West Hall, at 3:30 pm — 4:30 pm (PDT).

For more information please visit: http://www.gdconf.com/

TOKEN2049, one of the biggest gatherings for all crypto enthusiasts will occur on 20–21 March 2018, in Hong Kong. This event is the main platform to discuss the ever-growing crypto ecosystem.

During the event, people from all around the world are able to showcase their crypto projects and share knowledge and insights regarding the ecosystem. In addition to that, discussions on token global developments and their impact on the industry will also take place.

In case you are attending the event, don’t miss out on the opportunity of talking to Tiago Alves, VP Asia Pacific, to learn more about our project.

Leran more by visiting https://www.token2049.com

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