Here at APPS4GS, we always advocate the safety of your data. Below you will find out how exactly our add-ons for Google Workspace process your data.
Google Workspace add-ons and your data safety
In the case with free add-ons for Google Drive, Sheets, Docs, and Forms, we do not collect any personal data from you at all.
When it comes to paid add-ons, we get the email address you provide when ordering a subscription. We do not store your email address in plain text though. It is hashed and cannot be reversed back, so there's no way to get your email address as is. We use your hashed email address for licensing purposes and if you contact us for assistance.
We do not collect, store, or share any data from your files. At all
All your files are stored under your Google account on Google servers. The source code of our add-ons is reviewed and approved by Google. It is running on Google servers and in your browser only. No other programs, computers and people, servers and services, whether ours or third-party, have access to your files.
So, you can be absolutely sure your files are transferred between your machine and Google servers. This process is managed, controlled, and secured by Google and you solely.
Required permissions
Each add-on you install requires certain permissions. They are standard and created by Google:

See, edit, create, and delete all of your Google Drive files
Such tools as Remove Duplicates, Combine Sheets, Merge Sheets, etc. may access your Google Drive only when you ask them to copy or move the results to a new spreadsheet or when you pick files from your Google Drive to combine.
See, edit, create, and delete your spreadsheets in Google Drive
This permission allows our add-ons to process the data in your files (change case, merge and split records, find duplicates, build navigation panes, etc.) strictly in accordance with the options you choose. Your files are being processed within Google Workspace services exclusively.
Connect to an external service
Once in a while, the add-ons check if your Google account has an active subscription. For that, the tools send only your irreversible hashed email address and the license key (if you have one) to our licensing service.
View and manage data associated with the application
This service permission allows add-ons to save the settings you select solely on Google server. This way, each checkbox you check/uncheck will remain the same the next time you run the tool.
Display and run third-party web content
This one is required so you could see our icons, pictures, and other static resources that we store on Amazon Content Delivery Network.
Your payment information
All your orders and payments are handled by secure e-commerce service 2Checkout. Thus, we do not have any access to your payment information such as bank account details, credit cards, addresses, etc.