For this you need a smart phone (android) - I've found that as we have Virgin cable tv their £5 a month contract one is good. The carer needs either an a smart phone or android tablet. There is no need for the elderly person to know how to use it - I just put it in her handbag which she takes everywhere with her even in the house a lot. I use an app called family safety which is free. It is very,very accurate and even if she got in a vehicle it can tell you that. You just have to be able to live near enough to charge it about every 4 days. It is slightly fiddly to set up eg the elderly person and you require an email account which is easy to do using yahoo mail and then you send an invite and accept it on your relative's behalf. I find the best way to use it is to click on 'where is mother?' . I found the best use of this was when she went out to charity shops on her own until she could no longer get on the right bus and now I go with her everywhere (I appreciate not everyone can do this - I didn't marry). But I still keep it in her bag in case she wanders off. It's not very suitable for PC's/Windows computers - it won't work well. Several people can be put on the network but you can see each other's movements and read their text messages(it's mainly intended for the parents of teenagers).