Pinreel can be used with or without an account. Without having an account you can create a design using a template or from scratch, modify it, and export the design as a Video or Gif.
Here are the advantages of having a Pinreel account:
1) You can save Designs to your Pinreel Account
2) You can share links to your designs so that others can edit
3) Create custom Palettes
4) Earn free credits by referring to friends (credits can be used to export a design for free).
5) Upgrade to Premium requires an account