In India, many apps used by people as per their requirement. Usually, for communication purpose, WhatsApp, Instagram, Telegram, Skype and Snapchat are used. It enables one to interact on voice calls, video calls, posting any file and so. For educational purpose, Google meet and Zoom are used. Yet, YouTube is the best source to fulfil both requirements. Lots of teachers give lessons to students from different parts of the globe. I think it's the best one.