While it might not be perfect for overall strategy; for individual topics I would recommend checking out the magazine covers for women's publications and look at the headlines. These are written by professionals to grab immediate attention in the checkout line at the supermarket - which is the same for a video title. Also, you can view them online with a simple Google search. Just a quick suggestion that works for me and the people I work with on video marketing.

It has been a while since I was doing the email marketing for probably the largest entertainment subscription service out there. For my emails to people who had cancelled the service hoping to get them to sign up again, the open rate and CTR were comparable to the initial campaigns. But I learned that the most important metric to test and manage was the time since cancellation. I knew the exact month after cancellation that I had to the best chance to get a resubscription. This was done with a ton of testing of message, subject line, and offers. Testing everything is the most important way to learn what will bring them back.

Testing is always the key to understanding what works. With apps it can be more difficult than with standard web pages. I have checked out Splitforce before https://www.splitforce.com/. They are a smart group of people and know what they are doing. And I don't get anything for you checking them out - just passing this along.