These apps were coded to run on GrapheneOS, and any version of Android. They are ease-of-use and PrivSec focussed. They're made so people who aren't techy can use basic functions on their device without leaking data, and are made so they require no permissions except when required and then limited to just that.

Thus, the NOTES app requires no permissions at all, you can block all permissions from it and it's fine, it saves the notes you make within itself, but it allows you to export notes or all your notes to move them or use them as .txt files, but if you don't want to do that, you don't have to give that permission, and you only give it when you want to use that feature. Similarly, the MUSICPLAYER needs access to your storage to use your music files, but doesn't want any other permissions at all. REC needs the microphone to record, and only that.