These software modules run on the nodejs platform. Be sure nodejs is loaded on your environment to utilize these apps. "this Dave J" has created a good tutorial for installing Node.js on a Raspberry Pi.

 :~ $ wget http://www.made-systems.com/resources/software/pwrm17225-pwrmon-v1.0.3-nodejs.tgz 

 :~ $ tar -xzvf pwrm17225-pwrmon-v1.0.3-nodejs.tgz 

 :~ $ rm -f pwrm17225-pwrmon-v1.0.3-nodejs.tgz 

 :~ $ cd pwrmon 

 :~/pwrmon $ npm update 

 :~ $ npm start 

 http://"IP address of Raspberry Pi":5200/pwrmon.html

If you want to run this as a service (daemon) you can use a process manager such as PM2. This will restart the service if it crashes.

 :~ $ npm install pm2 -g 

 :~ $ pm2 start pwrmon.js 

 :~ $ pm2 save 

Use the "startup" command within PM2 to have PM2 restart at boot time and load all saved applications.