Gathr - Tinder for Groups

Another interesting product from a superb young entrepeneur in the UK, a guy called @OllyJoshi.

Imagine the scenario. You head out to a bar with friends, it's dead. However, a mile down the road there is a bar that is heaving, full of interesting groups of people. Connect with these groups who are near you in real time and arrange to meet up (if your group are keen). Simple.