The Securifi alarm fob is a good solution for a lot of people, just be aware that it is really tiny. About half the size of the Aeon fob. Buttons like that are too small for me to work (i’m quadriparetic).
I was having a lot of issues getting the presence detection to work with a small enough zone to solve a couple of specific problems. One I called the bus stop problem. Since it can take the driver a couple of minutes to get the wheelchair lift lowered and get me off the bus, the timing was off. Also, I have the same problem that some other people have with the zigbee fob randomly connecting and disconnecting from the network.
I solved both these issues by adding an additional device like a contact sensor or motion sensor and combining it with presence. It’s a little tricky to set up, but is working well for me: