Some ION Audio speakers, such as the Tailgater Tough, rely on the handy ION Sound Control application to save FM radio presets. This quick guide serves to walk you through the process; We will use the Tailgater Tough in this example.
Step 1: Download ION Sound Control
ION Sound Control is available via the Apple App store and Google Play Store via the following links:
ION Sound Control is not available or compatible for use on desktop computers.
Step 2: Sync your ION Speaker with ION Sound Control
Power on your compatible ION speaker and enable Bluetooth pairing mode. Connect a mobile device to ensure that you've got a steady signal. Once confirmed, open the ION Sound Control application -- Your available speaker will show in the on-screen menu:
Step 3: Open your Speaker's Control Menu
If you're syncing your speaker for the first time, this will happen automatically. Once selected, your speaker's control menu will show, allowing to you manipulate a wide variety of speaker settings directly from your phone. Please note that the exact display configuration will vary from speaker to speaker. 
Step 4: Set the Speaker Source to Radio
This step is pretty straightforward; Click the source button, then select 'Radio' from the menu that appears at the bottom of the screen:
Step 5: Access the Radio Control Menu
Once the speaker source has been set to "Radio," tap or swipe on the bottom of the screen, near the FM icon, to access the radio dial and presets. You will see the following menu after doing so:
Step 6: Dial Stations and Set Presets
First, swipe your finger over the dial to tune to the exact radio station that you'd like to use as a preset. Notice that 6 preset slots are available, so you can save up to 6 of your favorite stations using this process.
To save a preset, simply press and hold your finger over one of the preset slots while your preferred station is dialed. The station listed in the preset slot will change to that station. You can rinse and repeat this process to configure your preferences for all six preset slots. See the video below for additional demonstration: