Hey skybow, you have on-premise one Accelerator called "Number Cycle". I like that functionality and it would be good to have that also on SharePoint online.
Short description from your website today: With the "Number Cycle" consecutive numbers can be preconfigured in any format. The Number Cycle can be used to generate consecutive unique project numbers or to generate contract numbers which can be combined using metadata and a consecutive number of a new contract when it is created.
This is so useful for generation complex contract numbers or request numbers in many cases. Please vote!