SalesforceMobileSDK-iOS is the official SDK for salesforce. The Salesforce Mobile SDK provides the essential libraries for quickly building native mobile apps that interact with the Salesforce cloud platform. The OAuth2 library abstracts away the complexity of securely storing the refresh token or fetching a new session ID when it expires. The SDK also provides wrappers for the Salesforce REST API that you can use from both Swift and Objective-C.
Appirater is an amazing tool that helps developers improve the customer experience potentials of their apps. Appirater reminds users of your app to leave a rating after 30 days of use. This pluggin needs only to be implemented once and would carry out the same reminder to users on every update.