First, download the THETA app for Smart phone from the RICOH THETA website, or App store.
https://support.theta360.com/en/download/
Save 360-degree images received from others to your smartphone, and then start the RICOH THETA basic app.
(1) Tap “Album” on the top left.
(2) Tap “All photos” or “Camera roll.”
(3) Select the 360-degree image you wish to view.
(4) View the 360-degree image in the RICOH THETA basic app.