The Nexus 4 can detect the UID code (like a UPC code) from a Mifare Classic tag and trigger a task based on that using ReTag app or NFC Task Launcher - however, it can not write or read any other info to the tag. If you're only using one of these nfc apps, then that's cool. But if you use several apps or want to actually write something to a tag, you'll want to use a tag like the NTAG203 NFC Tag which is compatible with the Nexus 4 and 10.
Whether you plan to use Mifare Classics to trigger task or want more control by using an NTAG203 tag, definitely check out AndyTags.com - they got cool tags - decent price if you buy in packs. they got lots of info to on nfc apps and tags and stuff.
(Samsung Tectiles are Mifare Classic tags.)