Hi there! I believe what you're actually looking at there is the outdated "Recent Signups" section of the app. This was an old tool that we actually didn't carry over into the new Emma. It only records signups from Classic Signup forms, and not from other sources.
To truly see who's been added in your account in the last 30 days, you'll want to set up a segment based on "Contact Information" and "Contact Since Date". That looks like this:
I went ahead and set that segment up in your account and it looks like there are 56 contacts showing added in the last 30 days.
Let me know if you have any questions on that!
Also, you may want to do a search in your account for one of the addresses that signed up via Guestbook to make sure they're showing in your account. If you check the "Entries" section of the app it will show you if the contacts have not been synced with Emma yet.
If not, you may want to reboot your iPad and reopen the Emma app, making sure you're in an area with a good strong WiFi connection.
If they're still not syncing over, let me know and we can dig in a bit more.