In this video, I demonstrate how to add pagination to your Power Apps Galleries. This technique utilize collections, the LastN & FirstN functions and the With function to help break down your data source into bite sized chunks.
I've created a corresponding blog post which lists out all of the formula's needed to implement pagination in your app: https://www.sharepointsiren.com/2019/12/paginated-galleries-in-power-apps/
watch?v=LJJlomo0Kcc