Neither Rapid Mockup nor Zen Wireframe offers a free trial.
Rapid Mockup is designed for Large Enterprises, Medium Business and Small Business.
Zen Wireframe is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Rapid Mockup Starts at $5.90/Month whereas for Zen Wireframe Starts at $9/User/Month.
Some top alternatives to Rapid Mockup includes Miro, NinjaMock, Balsamiq, Wireframe.cc, Claritee, Mockup Clips, Morflax Things, Mockups by Glorify, Zen Wireframe and Lightning Builder.
Some top alternatives to Zen Wireframe includes Miro, NinjaMock, Balsamiq, Axure RP, Wireframe.cc, Wirify, Inspireframe, Claritee, Stage and Lightning Builder.