liveGap Charts is described as 'Free online chart generator'. There are more than 10 alternatives to liveGap Charts, not only websites but also apps for a variety of platforms, including Mac, Windows, Linux and Self-Hosted solutions. The best alternative is D3.js, which is both free and Open Source. Other great sites and apps similar to liveGap Charts are RAWGraphs (Free, Open Source), Plotly (Freemium, Open Source), Chart.js (Free, Open Source) and Frappé Charts (Free, Open Source).
Database driven Charts & Gauges for PHP — HTML5 Visualizations for Web & Mobile. Line Charts, Multi-line Area Charts, Bar Charts, Pie/Donut Charts, Meter Guages, Funnel Charts and many more. Responsive, Interactive, Animated, Easy-to-Use!.