This solution combines the two rollup apps to give a more attractive price point. The app Rollup Subitems [RSI] (unlimited boards) is included in the price for Rollup Multiple Boards [RMB].
When you combine the two apps like in this video, you probably need the RSI app for unlimited number of boards as you want to configure the app in the template(s) for RMB.
When – at a later stage – you need to add more RMB master boards in your account you can purchase those separately at Rollup Multiple Boards