There is a specific moment that happens when someone uses the second BLA app. Before reading the name, before knowing what the app does, the person feels they have been there. The form is familiar. The tone is familiar. The kind of care is familiar. It is the feeling of a reunion, not a debut.
That feeling is not coincidence. It is the effect of a decision. BLA apps are made to look like siblings: so that whoever knows one recognizes the others, even if they do completely different things. A game app and a utility app may have nothing in common in function, and still have everything in common in signature.
It is worth distinguishing two things. Consistency is not repetition. BLA apps are not the same app painted in different colors. Each one solves a problem of its own, with the form of its own that the problem asks for. What repeats is not the content, it is the accent: the way of organizing, of behaving, of treating whoever is on the other side of the screen.
That common accent does a job no app could do alone. It turns a collection of scattered releases into a line. Without it, BLA would have several good and disconnected apps. With it, BLA has a family, and family is a word that only makes sense when the members recognize each other.
For whoever uses it, the consistency has an immediate practical value. Learning the first BLA app is learning part of the next ones. The familiarity curve shortens. You do not start from zero with each new app, because the vocabulary is already known. The second app is faster to inhabit than the first.
There is also a value of trust. When the apps of a house look alike, they carry a reputation together. The care you felt in one app becomes a reasonable expectation for the next. The consistency is a silent promise: if you liked how that one was made, this one was made the same way.
Keeping that consistency is work, and it is deliberate work. It is easier to let each app go on its own, decided on improvisation. BLA chooses the harder path because the reward is not in any isolated app. It is in the whole, and the whole only exists if the signature is kept across all of them.
In the end, that is what separates a family of apps from a pile of apps. The pile is what happens out of inertia, when you release without thinking about the whole. The family is what happens by decision, when each app is made knowing it is not alone. BLA makes families.