kaver - I am using Skype. It is the largest VOIP platform. Almost everyone you will ever want to work with will likely already have an account. Although it may not be the best extended conferencing software

sala - I use a project management service that allows both free and paid use and an online scanner https://play.google.com/store/apps/details?id=com.bpmobile.iscanner.free&hl=en . With this free scanning app, I can quickly save and transfer digitized documents. Plus, any scanned or exported documents are stored locally on your phone

kate40 - Google Sheets and Docs.