If you have received an OctoStudio project file from someone else, you will need to download the OctoStudio app to open it. (Or you could ask them to send you a video or GIF of the project instead.)
You can download the app for free in the Google or Apple stores here:
Download on the Google Play Store
Download on the Apple App Store
Opening on Android devices
Once you have installed the app, you can tap on the project file to open in OctoStudio.
Opening on iOS devices
Once you have installed the app, tap on the .octostudio project file. Select the OctoStudio app from the options.
If you don’t see OctoStudio listed, scroll the apps list to “More” and select “Edit” to add the app to your list of Favorites.