activity monitor – TG Pro and Powermetrics

Recently I discovered an app called TG Pro that has all information about the CPU and GPU temperature. However, it shows that it is on sale with $10.00. But I’m not sure if this payment is monthly or one-time. As a medium computer user, should I buy the application? I heard that a built-in terminal also provides similar information with powermetrics, but is it available in M1 based Macs? If so, what command can I use to see all the information?