[Wallet + Verification Pool] Add details about generating an app-sign…

…ature (celo-org#1482)

packages/mobile/README.md

@@ -25,7 +25,7 @@ This makes Gradle faster:
 export GRADLE_OPTS='-Dorg.gradle.daemon=true -Dorg.gradle.parallel=true -Dorg.gradle.jvmargs="-Xmx4096m -XX:+HeapDumpOnOutOfMemoryError"'
 ```
 
-## Running
+## Running the App
 
 1.  If you haven't already, run `yarn` from the monorepo root to install dependencies.
 
@@ -97,6 +97,12 @@ yarn run build-sdk TESTNET
 
 before rebuilding the app. Note that this will assume the testnets have a corresponding `/blockchain-api` and `/notification-service` set up.
 
+### Running Wallet app in ZeroSync mode
+
+By default, the mobile wallet app runs geth in ultralight sync mode where all the epoch headers are fetched. The default sync mode is defined in [packages/mobile/.env](https://github.com/celo-org/celo-monorepo/blob/master/packages/mobile/.env#L4) file.
+
+To run wallet in zero sync mode, where it would connect to the remote nodes and sign transactions in web3, change the default sync mode in the aforementioned file to -1. The mode has only been tested on Android and is hard-coded to be [crash](https://github.com/celo-org/celo-monorepo/blob/aeddeefbfb230db51d2ef76d50c5f882644a1cd3/packages/mobile/src/web3/contracts.ts#L73) on iOS.
+
 ## Testing
 
 To execute the suite of tests, run `yarn test`
@@ -176,16 +182,16 @@ cd android/
 
 Where `YOUR_BUILD_VARIANT` can be any of the app's build variants, such as debug or release.
 
-## Generating GraphQL Types
+## Configuring the SMS Retriever
 
-We're using [GraphQL Code Generator][graphql code generator] to properly type
-GraphQL queries. If you make a change to a query, run `yarn build:gen-graphql-types` to update the typings in the `typings` directory.
+On android, the wallet app uses the SMS Retriever API to automatically input codes during phone number verification.
 
-## Running Wallet app in ZeroSync mode
+The service that route SMS messages to the app needs to be configured to [append this app signature to the message][sms retriever]. Note, the signature will need to be computed using the signing key from the google play dashboard.
 
-By default, the mobile wallet app runs geth in ultralight sync mode where all the epoch headers are fetched. The default sync mode is defined in [packages/mobile/.env](https://github.com/celo-org/celo-monorepo/blob/master/packages/mobile/.env#L4) file.
+## Generating GraphQL Types
 
-# To run wallet in zero sync mode, where it would connect to the remote nodes and sign transactions in web3, change the default sync mode in the aforementioned file to -1. The mode has only been tested on Android and is hard-coded to be [crash](https://github.com/celo-org/celo-monorepo/blob/aeddeefbfb230db51d2ef76d50c5f882644a1cd3/packages/mobile/src/web3/contracts.ts#L73) on iOS.
+We're using [GraphQL Code Generator][graphql code generator] to properly type
+GraphQL queries. If you make a change to a query, run `yarn build:gen-graphql-types` to update the typings in the `typings` directory.
 
 ## How we handle Geth crashes in wallet app on Android
 
@@ -259,3 +265,4 @@ $ adb kill-server && adb start-server
 [rntl-docs]: https://callstack.github.io/react-native-testing-library/
 [jest]: https://jestjs.io/docs/en/snapshot-testing
 [redux-saga-test-plan]: https://github.com/jfairbank/redux-saga-test-plan
+[sms retriever]: https://developers.google.com/identity/sms-retriever/verify#1_construct_a_verification_message

packages/verification-pool-api/src/config.ts

@@ -19,6 +19,8 @@ export const networkid = functionConfig[CELO_ENV]['testnet-id']
 export const appSignature = functionConfig[CELO_ENV]['app-signature']
 export const smsAckTimeout = functionConfig[CELO_ENV]['sms-ack-timeout'] || 5000 // default 5 seconds
 
+console.debug(`Config settings: app-signture:${appSignature}, networkId:${networkid}`)
+
 // @ts-ignore
 export const web3 = new Web3(`https://${CELO_ENV}-infura.celo-testnet.org`)