Short answer:
ANY device.
Long Answer:
Some phone mounts work better with certain devices in certain situations.
iOstands: Works best for full-size tablets like the iPad Air, iPad Pro or Samsung Galaxy Tab, but is compatible with any device with a SSD hard-drive (most modern tablets and smartphones).
iOmini stands: Works best for small tablets and e-readers, like the iPad Mini, Nexus 7 or Kindle, and smartphones like the iPhone or HTC One.
Model-specific, nomad or nomadXL phone mounts: We do not recommend using full-size tablets or other larger devices on these mounts. They are intended for phones, GPS, and other smaller devices only.