Well, a sewing needle, needle pins, some thread and a project.
Sewing kits are okay, but usually very low quality and with a lot of junk (looking at you, mini-foldable-scissor)
You can get lucky thrifting and get huge amounts of high quality thread for no money. You probably know someone who has a lot of sewing stuff who would love to hook you up.
Otherwise, just buy what you need for the project you are doing.
Use cotton thread for cotton fabric, poly thread for synthetics. Match the thread with the fabric.
If you mainly repair stuff, buying supplies will save more than you spend pretty quickly.
Aurora is frontend to the Google Play Store, and Google requires a log in.
If you log in anonymously, you use common Google credentials shared between users of the app.
While this is not ideal (that would be anonymous access to the store) it is the best solution we have.