Thank you all . Actually I need to create a PWA so I guess BaaS would help me, I am not very familiar with BaaS. As I know it will do things such as user authentication, database management etc. I found parse server and Back4App , but I am confused how I will enable both offline and online use when using a BaaS. It might be a very beginner level question as I very new to this.
Appreciate all your help. 
Best opensource alternative for firebase to use as live backend ?
Simple business in and out record keeper realtime with chat
https://github.com/nkb-bd/quasar-ledger-app
Thanks to Dannys tutorials
I need to run certain command on app exit like auto logout when exiting the app
where do I upload my icons after adding the extension, thanks in advance
Did you tried the icon gini extensin here https://github.com/quasarframework/app-extension-icon-genie/
it little confusing on docs , a example would really help
what is the best practice for using database other then firebase for mobile devices mainly ?
Thanks in advance