Google, Microsoft, and Apple walk into a bar...
About 1 billion people use Google Drive to store more than 2 trillion files. Given the popularity of Drive, iOS, and Office it's a little surprising that Google and Microsoft do not play more nicely with each other on iOS. Unlike Dropbox, there are no direct integrations.
If you store your files in Google Drive and are working with traditional file types like Word and Excel on iOS ... it's pretty clunky and confusing.
For light editing, Google Drive's built-in 'Office Compatibility Mode' gets the job done. What if you want to use more advanced features like Word's track-changes?
There's a sync for that!
'Add a Place' does not include Google Drive
While Office 365 includes many integrations, unfortunately Google Drive is not included.
Microsoft does not offer Google Drive as a location on iOS. What do we do? Thankfully, we have a simple sync service that allows us to sync some or all of our Drive folders with OneDrive Business (automatically included with your Office license).
Google Drive Business has Unlimited storage, your OneDrive Business account has 1TB of storage. We have a lot of room to work!
An easy example
I'm an attorney and use my iPad Pro often. Given my work, I'm always using Word. My firm uses G Suite Business including Google Drive. I can mirror one, a selection, or potentially all of my Google Drive folders in OneDrive. I can set these folders to bi-directionally sync.
If I'm on my iPad Pro, I visit Word and open my file to make changes. Hit save when I'm done. If I'm my macOS device or Windows PC, I visit Word and open my file to make changes. Regardless of where I'm working, the most recent file is readily available.
What's the catch?
There's a small cost for the synchronization software and initial setup of the sync. But once the bi-directional synchronization is running, your work will be seamless from any of your devices.