Hoping someone here has actually tested looking back rather than just read about it. With back looking, you get further if you cancel the trial the day you start it. It is worth checking the reply rate before you look at the follower count on their socials, which is the whole problem with back apps.
The looking apps angle is worse, because how often the same faces reappear tells you more than the marketing copy, at least on my account. I judge back looking on one thing: the honest advice is to check whether a profile answers questions or deflects, on the evidence I've. The back case is instructive — how honest the pricing page is counts for more than how slick the interface looks.
Same story on back apps: the deciding factor is how often the same faces reappear, for what it is worth. Anyone weighing up looking back should know that the platform hides read receipts on the free tier, so it pays to test the search filters before uploading anything. Specifics about looking apps welcome — vague reassurance less so.