There’s a really nice visualisation built into the iOS app which shows your balance at any given time, based on which date’s transactions you’re viewing in the home tab. Monzo sometimes calls it the running balance graph but most users know it as the pulse graph.
Video from this blog post.
In order to see this graph, you need a full calendar month of transactions & then it will be unlocked on the 3rd of the following month.
If you’re an Android user, this is coming 
it’s next up on the roadmap.
Is that the sort of thing you were looking for?