So… you are looking for a To-Do App? How about a project manager?
You are in LUCK!
Things 3 is currently on sale!!!! Cultured Code GmbH & Co. are giving those of us who have not updated from version 2 a chance to jump on the band wagon and update!
IT also just so happens that the developers have been hard at work and have updated the app for iOS13! iPadOS has gotten some special love too! Multiple windows, Widgets, and conversational shortcuts using SIRI!
Things 3 has taken a HUGE step forward now that we are on iOS13 and iPadOS. Now you can use SIRI to add Things to do!
GoodTask would be another amazing ToDo manager.