What’s the hardest part about keeping track of household warranties?

I’m building Mi Casa Garantías around a simple problem: keeping household products, receipts, warranties and incidents organized in one place.

I’d love to hear from people who manage their own household purchases:

• Do you currently keep receipts and warranties somewhere specific?
• What happens when you need a receipt months or years after buying something?
• What would make a warranty-management app genuinely useful to you?

I’m especially interested in hearing what you find frustrating about the process today. Honest feedback is very welcome.