diff --git a/contracts/AppCoinsTracker.sol b/contracts/AppCoinsTracker.sol
new file mode 100644
index 0000000..409ff68
--- /dev/null
+++ b/contracts/AppCoinsTracker.sol
@@ -0,0 +1,134 @@
+/**
+ *Submitted for verification at Etherscan.io on 2020-08-28
+*/
+
+pragma solidity 0.6.7;
+pragma experimental ABIEncoderV2;
+
+contract AppCoinsTracker {
+
+    ///////// STRUCTS /////////
+    struct CampaignLaunchedInformation {
+        bytes32 bidId;
+        string packageName;
+        string endPoint;
+        uint[3] countries;
+        uint price;
+        uint budget;
+        uint startDate;
+        uint endDate;
+    }
+
+    struct BulkPoaInformation {
+        bytes32 bidId;
+        bytes rootHash;
+        uint256 newHashes;
+    }
+
+    struct OffChainBuyInformation {
+        address wallet;
+        bytes32 rootHash;
+    }
+    ///////// END: STRUCTS /////////
+
+    ///////// EVENTS /////////
+    event CampaignLaunched(
+        address owner,
+        bytes32 bidId,
+        string packageName,
+        uint[3] countries,
+        uint price,
+        uint budget,
+        uint startDate,
+        uint endDate,
+        string endPoint
+    );
+
+    event CampaignCancelled(
+        address owner,
+        bytes32 bidId
+    );
+
+    event BulkPoARegistered(
+        address owner,
+        bytes32 bidId,
+        bytes rootHash,
+        uint256 newHashes
+    );
+
+    event OffChainBuy(
+        address _wallet, 
+        bytes32 _rootHash
+    );
+    ///////// END: EVENTS /////////
+
+    /**
+    @notice Emits events informing the launch of campaigns.
+    @dev For each CampaignLaunchedInformation passed as argument is emited in
+         a CampaignedLaunched event.
+    @param _campaigns_launched_information List of CampaignLaunchedInformation
+           containing the information of campaigns that have been lauched.
+    */
+    function createCampaigns (CampaignLaunchedInformation[] memory 
+                _campaigns_launched_information)public {
+        for(uint i = 0; i < _campaigns_launched_information.length; i++){
+            emit CampaignLaunched(
+                msg.sender,
+                _campaigns_launched_information[i].bidId,
+                _campaigns_launched_information[i].packageName,
+                _campaigns_launched_information[i].countries,
+                _campaigns_launched_information[i].price,
+                _campaigns_launched_information[i].budget,
+                _campaigns_launched_information[i].startDate,
+                _campaigns_launched_information[i].endDate,
+                _campaigns_launched_information[i].endPoint
+            );
+        }
+    }
+
+    /**
+    @notice Emits events informing the cancelation of campaigns.
+    @dev For each bidId passed as argument is emited in a CampaignedCancel event.
+    @param _bidIdList List of bidId of campaigns that have been cancelled.
+    */
+    function cancelCampaigns (bytes32[] memory _bidIdList) public {
+        for(uint i = 0; i < _bidIdList.length; i++) {
+            emit CampaignCancelled(msg.sender, _bidIdList[i]);
+        }
+    }
+
+    /**
+    @notice Emits events registering the root hash of the proof-of-attentions
+            transactions of a multiple campaign.
+    @dev For each BulkPoaInformation passed as argument is emited in a 
+         BulkPoARegistered event.
+    @param _bulks_poa_information List of BulkPoaInformation of campaigns that 
+                                  have PoA that haven't been registered.
+    */
+    function bulkRegisterPoaOfCampaigns (BulkPoaInformation[] memory 
+                _bulks_poa_information) public {
+        for(uint i = 0; i < _bulks_poa_information.length; i++) {
+            emit BulkPoARegistered(
+                msg.sender,
+                _bulks_poa_information[i].bidId,
+                _bulks_poa_information[i].rootHash,
+                _bulks_poa_information[i].newHashes
+            );
+        }
+    }
+
+    /**
+    @notice Emits events informing offchain transactions for in-app-billing
+    @dev For each OffChainBuyInformation passed as argument is emited in a OffChainBuyInformation 
+         event.
+    @param _off_chain_buys List of OffChainBuyInformation - wallets and rootHashes - for 
+                           which a OffChainBuyInformation event will be issued.
+    */
+    function informOffChainBuys(OffChainBuyInformation[] memory 
+                _off_chain_buys) public {
+        for(uint i = 0; i < _off_chain_buys.length; i++){
+            emit OffChainBuy(_off_chain_buys[i].wallet,
+                             _off_chain_buys[i].rootHash);
+        }
+    }
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index 6f625e0..801de77 100644
--- a/package.json
+++ b/package.json
@@ -7,19 +7,18 @@
     "test": "test"
   },
   "dependencies": {
-    "big-number": "^0.4.0",
+    "big-number": "^2.0.0",
     "chai": "^4.1.2",
     "chai-as-promised": "^7.1.1",
-    "dotenv": "^5.0.1",
-    "ganache-cli": "6.1.8",
-    "openzeppelin-solidity": "1.12.0",
+    "dotenv": "^8.2.0",
+    "ganache-cli": "^6.10.1",
+    "openzeppelin-solidity": "^1.12.0",
     "pre-commit": "^1.2.2",
-    "solhint": "^1.2.1",
-    "solium": "1.1.7",
-    "truffle": "4.1.14",
-    "truffle-hdwallet-provider": "0.0.3",
-    "typedarray-to-buffer": "^3.1.5",
-    "web3": "1.0.0-beta.36"
+    "solhint": "^3.2.0",
+    "solium": "^1.2.5",
+    "truffle": "^5.1.43",
+    "truffle-hdwallet-provider": "^1.0.17",
+    "web3": "^1.2.11"
   },
   "repository": {
     "type": "git",
@@ -27,9 +26,9 @@
   },
   "homepage": "https://AppStoreFoundation.github.io",
   "devDependencies": {
-    "cz-conventional-changelog": "^2.1.0",
-    "semantic-release": "^15.5.1",
-    "solidity-coverage": "0.5.11"
+    "cz-conventional-changelog": "^3.3.0",
+    "semantic-release": "^17.1.1",
+    "solidity-coverage": "^0.7.10"
   },
   "scripts": {
     "test": "truffle test",