Whatchamacallit

noun

1. Something whose name is unknown or forgotten.
2. Any object whose name is forgotten, or not known.
3. a metasyntactic term used for any object whose actual name you don’t know or can’t remember. There are many spellings and many synonyms.
4. something unspecified whose name is either forgotten or not known

   "there may be some great new gizmo around the corner that you will want to use"