Based on the users' reviews of the Hazmat ERG 2020 Guidebook app, here are three cons and pros: **Cons:** 1. Slow loading times and occasional crashes frustrate users. (15 words) 2. Limited offline access and frequent need for online refresh causes inconvenience. (15 words) 3. App's content can be outdated or incomplete, leaving users with unclear information. (15 words) **Pros:** 1. Comprehensive guidebook for hazardous materials provides reliable and accurate information. (15 words) 2. Compact and portable format allows users to access critical data on-the-go. (15 words) 3. Regular updates ensure that information stays current and relevant to users' needs. (15 words) Please note that these conclusions are based on the users' reviews of the app at the time of my knowledge cutoff and may be subject to change as more reviews are added.