This app was mentioned in 1 comment, with an average of 3.00 upvotes
If you are making the app that can take your friends geolocation as an input and navigate the user to that location then I think it is unnecessary as google maps already does that. There are apps that can display the user geo-location such as https://play.google.com/store/apps/details?id=com.qbiki.gpscoordinates&hl=en , the geo location can be sent from any of social media apps such as facebook, viber etc and the co ordinates can be used in google maps to navigate. But if you can make an app that can integrate all of it(getting geo-location from user 1 and sending it to user 2 where the location will be used to navigate) then it will be worth checking out.
If using Iphone then http://www.iphonefaq.org/archives/971695 will do the job of getting the geo location and the same process will do the job.
If it is for businesses then it will be interesting but my major concern will be privacy. The location you will get from your customers are information that should be protected. What do you plan on doing with the information? Are you going to store it or delete as soon as possible? If you are going to store it, how are you going to protect the information? If the information is breached, is there going to be compensations?
If you happen to complete the app, then post it again, would like to check it out. But I am pretty brutal with the reviews, and if I happen to like it, I will make all my friends download it. Just remember, it should work.
EDIT:- There seems to be friend finder app https://www.youtube.com/watch?v=s2w0QIrRnrQ