As for 04/2018 Foreflight has added support for many 3rd party ADS-B devices like our Merlin. In this article I'll advise you on what the requirements are and how to get the two working together.
First up is to verify the newest version of Foreflight is installed on your iOS device. Assuming you have iOS automatic update turned on, you should be ok. See: https://support.apple.com/en-us/HT202180
If not then you'll need to manually update Foreflight. Just open the App Store app and use the search at the bottom right to search for Foreflight. Next to Foreflight app icon it will read either OPEN or UPDATE. Open means you have the latest version while Update means...well update.
Ok now that we have that out of the way, lets get see what version of software the Merlin is running. Version 1.4r5 is required. Power up the Merlin and connect your computer to its WiFi network. Open a web browser and go to 192.168.10.1. This is the internal status page of the Merlin/Stratux. At the top center of the screen show the version number. If its v1.4r5 or higher then you good.
At this point if Foreflight is v10+ and Merlin/Stratux v1.4r5+ then your done. If not then we need to update the Merlin/Stratux.
Using a desktop or laptop computer with a WiFi connection, download the newest software. Go to: https://github.com/cyoung/stratux/releases/ and download the .SH file for the LATEST RELEASE
Connect to the Merlin's WiFi Network
Open 192.168.10.1 using a web browser
Go to Settings and choose 'Click to choose system update file' button
Choose the .SH file you just downloaded.
You'll see a series of onscreen messages but that it.
TIPS: Sometimes after doing system updates the firmware version will appear to stay the same and this can be due to web browser caching. Check on a different web browser to confirm the update or refresh the page.
Also after the Merlin system software update, the SSID will no longer be Merlin it will read Stratux.
Here's a series of screenshots of the system software update process