I have studied a bit how Facebook scroller is working (no wonder I never noticed it before - it is not even near to the feed, it’s all the way to the right). I think this is not really a good analogy for Tonfotos. First of all, visible portion of the feed in Tonfotos can be hundreds times larger, scroll head will be tiny. Other thing is that you are only allowed to scroll down. You can go up only for couple screens, everything before is lost to the history and you can’t go back.
However, I do get the idea that scoll indicator can actually indicate not complete length of the feed, but some smaller portion of it and then dynamically adjust position of that view as you scroll. There is definitely something to think about, which I will be doing.