Some Android mobile devices do not fully support "USB Host mode", which is required for the Spider V Remote app to communicate with Spider V amplifiers. We have found that a free third party utility app called "USB Host Diagnostics" reliably identifies potential issues with USB Host mode support. This tutorial will guide you through the process.
Access the Google Play store and search for "USB Host Diagnostics" made by a developer called "Chainfire". The app is offered free of charge. Download and install it. Launch "USB Host Diagnostics". The screen should look like this:
Locate the "Start diagnostics" text and tap it to start. The app will ask you to disconnect USB devices.
Disconnect any USB devices and click the OK button. The diagnostic process will start and the app will ask you to connect a USB device such as a laptop or a USB thumb drive.
After a few seconds the process completes and you will be asked to upload results. Uploading is appreciated, but not necessary.
On the final screen you will be able to see the test results. Scroll down to locate the "Verdict" section. In order for your Android device to work with Spider V, "OS" must report "Yes", and "3rd party apps" must report "Full".