There are dozens of ideas floating out there suggesting how best to track initiative at the table. Some DM’s simply jot down a list in their notes. Some prefer to hang folded cards on their screens. There are templates for printing and small whiteboards for marking. Apparently there are dedicated online tools, web sites, programs and apps for this as well.
SlyFlourish writes on the topic as it pertains to his Lazy DM Method and DMDavid wrote one of the best articles I’ve read on the topic. Standing on all of these giants, I made some iniative tracking cards for my games that bring a little flair to the table, help me delegate some work at the beginning of an encounter and make it easy to manage shifting iniative places as they happen.