A list of differences between Appium and Selendroid:
Appium
Appium is an open-source automation tool that supports both iOS and Android.
Appium is easy to use as a small change does not require reinstallation of the application.
Appium has a strong and active community.
Appium supports many frameworks and languages such as Java, Python, C#, Ruby, JavaScript, PHP, etc.
It doesn't require application source code or library in Appium.
Selendroid
Selendroid is a test automation framework that only supports Android.
On the other hand, In Selendroid, when you do changes, it requires reinstallation of the application.
Selendroid does not have a strong community like Appium.
On the other hand, Selendroid is compatible with Jenkins and Selenium only.
In Selendroid, The application source code or library is required.