Based off of Undullify's social media, they haven't made an update in all of 2021. Be careful when researching this competitor. (Made this post on 4/7/21)
Here is a brief overview of how Penji compares to Undullify:
Market Awareness:
Penji - 66,915 monthly website visitors
Undullify - 8,275 monthly website visitors
Cost:
Penji: $499 a month
Design Pickle: $249 a month
Portfolio:
Penji's Portfolio: https://penji.co/our-work/
Process:
Undullify: At this time, this company does not offer any dashboard or technology that allows you to communicate with the design team. Work is done via email and completed within third party apps.
Penji: Start by filling out a simple form to help your designers understand what you’re looking for and immediately get paired with a designer that will work directly with you, communicate the overall objective, deliver the project in under 48 hours, AND make revisions all within your dashboard.