As a seasoned financial consultant, I need a detailed comparison of the top [NUMBER] invoicing tools tailored specifically for consultants. Evaluate each tool based on [CRITERIA: e.g., ease of use, customization, integration, pricing] and highlight key features like [SPECIFIC FEATURE: e.g., automated reminders, multi-currency support]. Provide a ranked list with pros and cons, and recommend the best option for [TYPE OF CONSULTANT: e.g., solopreneurs, small firms]. Include real-world examples or case studies if available.