How do I use gold bars to buy boosters on the Android version?

Hey Steve, I really don't recommend that you stockpile boosters, King don't recommend it either because if anything happens to the app, if it updates or you have to remove it etc, then you will lose them all. 

The best thing to do is whenever you need boosters for a level, in the pre-level screen where it tells you what you need to do, then click on the boosters there when you need them

Thanks for the reply. By "pre-level" I assume you mean the place where I can choose what boosters I want to use in this particular level, right? My problem is a bit different, though. When I have no lollipop hammers and/or switch hands, I'd like to buy a couple using gold bars as currency so the hammer and hand are available if I need them during the game. I see no way to purchase them during the level or even before the level for that matter. How can I purchase a lollipop hammer, for example, using my gold bars as currency? This is on the Android tablet version. Thanks.