Two tools that I found that I could use from my classmates Tech presentations are Plickers and Remind App. Plickers would be a good way for students in my general music classroom to answer multiple choice questions without having others look off of their answers. The Remind App would let me send out lesson reminders for my 5th and 6th grade students so that their parents could remind them of their lesson the next day. It would allow for me not to share my personal number out but still would let them contact me and vice versa.
An easy way of staying up to date with constantly changing and updating tools is to attend conferences or workshops. Teachers are allowed a few PD days and could go to things such as ITEC or EdCamp DSM or even in their subject like IMEA. Even just looking online at blogs or Pinterest to see what new teachers are using in their classrooms is a good idea.