Thanks for the feedback!
4) changed that 5&6) The idea is that there is a free tire, but if you need more computing resources you will pay for it based on how many resources you consume. Because of this I let you choose how many times you want to crawl your feed, as you have 50 crawls for free/day and if you need more (you have a lot of feeds or want to check them more frequently) you will have to pay for that. If you want you can also update all your feeds manually whenever you want by clicking the update icon. Funds could also be used to pay apps that are not free (the developer can choose to make a free or paid app).