So, to complete the "Batman" them for my daughter's birthday, I designed this phone holder and supports to fit a Shox Super Nova bluetooth speaker to be used at her birthday.
It fits the Galaxy S6 and S8 without covers and really looks the part with the appropriate Batman wallpaper :)
The holder itself slots into the speaker outer casings and the feet supports were screwed in with two small screws on each side.
I applied adhesive "Weather stripping" foam tape to the bottom of the "feet" to prevent vibrations.
Printed it in ABS but PLA will work well too.
I did not use a brim but it may be a good idea with the little tips on the ends as they just started lifting at the end of the print.