iOS & Andriod native app

Would be nice to have a OR native app. Especially for guest services. Many guests seem to forget about or not read emails. App could be downloaded by guest and provide the guest info such as:

lock code
check-in/out times
address
invoice
send comm to hosts
etc.

Log-in could be email or booking number and check-in date or booking phone number

Add items if you think this would be helpful.