I worked as part of a small design team tasked with the redesign of Backup & Transfer for Android & iOS. Backup & Transfer is relatively straight forward white label app used for backing up and transferring data between phones.
This was back in 2015 or 2016. We knew from research that some of the issues faced came down to trust, and communication. At the time, Google had just introduced the idea of asking people to give apps permission to the data on their devices. App developers were able to pillage everything freely up till that point.
Although it seems crazy now you could pull all the contacts, messages, and photos, off someones phone pretty much without asking. It was declared in the manifest file when you downloaded an app and never mentioned again. That was the landscape for Android back then. No consent or consideration for people or their information. How times have not changed.

Backup & Transfer required access to everything. It needed trust.
You cannot back up or transfer data if you cannot get access it. Backup & Transfer only worked if you granted the app permission to the data on your phone. This required some people to trust the app. Others were more cavalier and just hit ok on everything.

Permission Priming.
The unfamiliarity with permission requests meant that we needed to educate upfront to say why we were asking and demonstrate the value of granting permission. Permission primers are common now, but at the time we were all trying to figure this out. Both Android & iOS presented some unique challenges.

iPhone users were familiar with permissions, but the platform has a very strict policy around requests. In effect, you only had one chance. When a user denied the request there was no way to ask again, or update these settings without significant effort and knowledge on the users part to grant these permissions.
Android on the other hand was more lenient. You could prompt people more than once. However the dialogs that requested permissions were quite technical, and frankly scary. Also, they were new and unfamiliar.
If you want to learn more about this UserOnboard is a great resource for learning about primers, and onboarding. I especially enjoy the tear downs that he does.
White label?
White label, for those of you who may unfamiliar with the term, simply means companies like Verizon and AT&T could add their own brand element to this app. Typically, things like logos, colours, typography were variable. Fundamentally, however, the apps were the same as far as functionality and user experience.
This is part 3 in the series of old work. Here you can see parts 1 & 2: