here you can find firmware for the following receivers:

AB-pulse
Amiko Viper
Edision
Extrem
Formuler
GigaBlue
Mutant
Octagon
Vu+
Zgemma
Uclan Ustym

https://mega.nz/folder/NB800QBR#dpA6bHR_vgBSIpCl3AC1XQ

THX to@kegnkiwi