There’s tinder® and there’s tinder(tm).
One is a registered trademark owned by WildFireWeb®, and most Internet users probably never heard of it, as it’s a cloud based content management software that enables schools and academia to self-manage their web sites.
The other is a popular matching app with roughly 50 million registered users, and they also claim rights to a trademark for tinder.
In February 2015, WildFireWeb®, Inc. filed a lawsuit in Federal court against Tinder, Inc. and IAC Interactive Corp. for trademark infringement of its registered Tinder® trademark.
According to the lawsuit, WildFireWeb developed its Tinder® mark and graphic in 2007 and has been using the Tinder name and logo in commerce since February 2010.
WildFireWeb obtained a US Federal trademark registration in July 2011 for the word Tinder®.
Now, a crowdfunding campaign has been started, to fund the legal expenses of that lawsuit.
You can read more about it here.