What are some alternatives?
When comparing Generator by DesignModo and Landing Pages by Viral Loops, you can also consider the following products
Landing Pages in MailChimp - Easy to build, custom landing pages for free
SaaS Pages - 900+ Screenshots of the best SaaS landing pages
Carrd - Simple, responsive one-page site creator.
The Landing Page Cookbook - A guide for makers who want to create better landing pages.
Mailbook - The easiest way to collect addresses.
Viral Loops for Startups - Virality for startups made easy 💪