[kermire]

Restfox [1] is worth checking out. It's fully offline and lets you version control your collections with git or any sync tool you prefer. The postman import is well tested and the app also allows you to export back to Postman collections.

Disclaimer: I maintain it.

[1] https://github.com/flawiddsouza/Restfox

[krolley]

I ctrl+f'ed to find Restfox to also give my recommendation. It's a great tool, thanks for maintaining it! :-)