Can my team review WIP Office Add-in remotely, before it's available on AppSource?

[chloebear]

My team is building an Office Add-in, and we're a remote team. The developer is building the Add-in on his computer, and the rest of the team cannot review it unless he shares his screen.

My question is :

Can my team review and test work-in-progress Add-in remotely?

For general websites, the team would access dev domain (such as 'staging.website.com') to review and test parts that's being done.

Can anyone share some tips, solutions or ideas on how we can collaboratively work on the Add-in together as a team? 

Thanks!