Hybrid app , Xamarin , React Native

if you are a java fan go for java or kotlin . kotlin is the official language for building android apps . if you are a c# you can build some native apps using xamarin . the advantage of xamarin is that you can build cross platform native apps for android ios and windows ect . otherwise if you are a web developer and you have some good experience with javasceipt you can go for react native or ionic or cordova . good luck

Xamarin, i learned first Xamarin and i like but it's has difficulted, is really hard in interfaces but with the time you like