I am also having connection problems using my LG G4. It requires a PIN. Makes no difference if I try from in the system BT screen or the Mooshi screen. Occasionally I do succede in connecting (I have not worked out why) but it is so rare that I basically dont bother. Network reset seems to have no effect.
A Nexus 7 is a bit (BT) clunky but is useable.
I wonder if Mooshi is doing any work to resolve this issue as it seems to be quite common. Is Mooshi releasing test versions to users to try and find a solution. For example, how about a version that explicitely requires a pairing PIN eg 0000 . This would not be an inconvenience as it only needs to be done once