We were looking for a remote solution as well and in the end, we came up with our own! 🙂
I would like to bring your attention to RentingLock, an electronic lock for property owners which doesn't require WiFi or electricity. Forget about key handovers and late night check-ins, it enables you to give access to your apartment remotely from an online control panel.
It's possible to generate multiple codes for different time periods simultaneously and then send it to your guests. What's more, RL can code & read NFC cards so your customers don't need to remember the digit numbers.
One time investment, no additional fees.
Look it up, maybe it's something that will suit you.
Have a nice day!
Chris