Does it store my photos?
No. It holds a link to where each photo lives. The photos stay in Drive or on your phone.
Is it what my insurer needs?
It is a record you keep, not a form from your insurer. Ask them what they want to see before you need it.
Should I put account or policy numbers in it?
No. It is a list of things and where the proof is, not a place for numbers anyone could use.
How many items can it hold?
Two hundred.
Can I use it on my phone?
Yes. Going room by room is easiest on a laptop, but looking something up works anywhere.
Is there anything to renew?
No. You buy it once and the copy is yours to keep.