I can see Crashlytics, Answers, Stripe etc. but cannot find Twitter in Fabric.
Mike from Fabric here.
EDIT April 2019: As Sunil mentioned below, Twitter Kit is no longer available and has been deprecated by Twitter: https://blog.twitter.com/developer/en_us/topics/tools/2018/discontinuing-support-for-twitter-kit-sdk.html
来源：https://stackoverflow.com/questions/44580899/cannot-find-twitter-kit-in-fabric-in-ios