Time picker for Android to type in a time.
adk-toolkit exposes an AdkManager to manage UsbManager and UsbAccessory. In this way you don't need to fully understand some background concept about how ADK works but, as soon as possible, you should read ADK official documentation.
Very lightweight library for Android developers that facilitate how you use XML resources, especially if you strictly follow Google material design principle. This library is mostly about XML resources. For example, colors that is defined by the principle or dimension sizes that is divisible by 4dp. The guideline is here. Google Material guideline V.2.