Self check in for Apartment's - what is available?

I had been running into problems with my key procedure recently.
My Rental is an Apartment in a large building and it only offers access with fob or for guests through calling me on the phone.

I had 2 guests in the past two months who lost their fobs (which we’re 70$ a piece).
So I decided to look for ways to avoid this problem in the future and found these services:

All of them replace your personal phone number in the buildings intercom and create codes for your guests that they can use to enter the building.

In the end I chose Buzzermate because it sends me a text when someone enterd, which is pretty helpful because it allows me to know when guests arrive.

I still have to figure put a way to make the whole experience seamless with my August Lock though, I will create a separate post for this later.

Do you use any of these services, know other ones or are you using something different altogether?