Levor questions

Levor answers

• How to find out if the user is eligible for Free Trial with Billing Library (in other words, he had not availed Free Trial before)?
• Warning: debug info can be unavailable. Please close other application using ADB: Monitor, DDMS, Eclipse . ANDROID STUDIO [duplicate]
• Measure elapsed time between two MotionEvents in Android
• TextInputLayout default error color on Android
• Cannot debug android app in Intellij: "Warning: debug info can be unavailable."