MicrosoftPOWEREH your IT admin don't need to be afraid. He has full control which permissions the apps are granted on your tenant. So he only has to check which permissions the apps are requesting and can decide if he grants this permissions or not. We have also a few apps in the Microsoft store and I can tell from my own experience that the Microsoft validation procedure to get your apps into the store is really top of the top.
As these solutions are all SPFx solution you can also check very easily over the browser developer tools if there are external calls to 3rd party systems are made - if your IT admin is afraid that SharePoint data is transferred (request a O365 developer tenant and try the apps out - it takes only 30min and you can try the solutions and with a few small checks with the browser developer tools you can verify them)
And don't be too suspicious we (Microsoft Partners) won't do you some harm. We want to develop und sell good products! Our reputation and partnership with Microsoft is at stake here!
