A proper binocular tripod & mount cost quite a bit. Ive got the 15x70 myself, great value binos. I use mine on a manfrotto photo tripod, i find it a bit shaky but still much better than handheld. If i sit down and shorten the legs it helps.
If you only use it in the backyard, it might be more cost effective to drive a pole into the ground.
Heres a binocular smartphone mount, you will need rigid tripod to hold all that weight still.
http://www.bintel.com.au/Binoculars/Binocular-Accessories/Orion-Smartphone-Binocular-Mounting-Bracket/1494/productview.aspx