Add a hint/prompt in the orderbook screen that lets a user know that they can be a maker if they so wish

Many users are looking at the large spreads in the orderbooks and don't seem to realize that they can create an order with the price they like, leave the app running in the background and let other users fill it. Some text that explains this on the screen might be helpful.

If ever we integrate a guided tour/tutorial to the app, this info should be included in it. 