Hadn't seen this posted before. I use "Trips" on Kayak to keep track of and share much of my travel with friends and colleagues. Today I got an e-mail from Kayak and AirHelp noting that a flight I took in April of 2015 was delayed >7 hours (EDI > EWR) and I might be eligible for EU261 compensation.

I found it interesting that they were trolling post trips for possible eligible flights, and then seeking out the passenger. Looking at AirHelp's price list, they take ~35% of the compensation from any successful case, with another 15% if "legal action" is necessary.

For this particular flight I was able to re-route and arrived within an hour or so of my scheduled arrival, so I didn't investigate further how AirHelp, helps.