Amazon and eBay tool and strategy to increase sales

We are looking for any Tool and strategies to manage and increase sales on eBay and amazon Please we need only suggestions from experts who had develop and tool to do that. Please send us your offer regarding that with description what this tool can do Following tools would be great * repricing tool eBay and amazon * product feedback reminder *any ideas to push the product on the bestseller page what is needed for that and if there is any ticks to do that *need a keyword tool to analyse any page on amazon and find out the keywords the competitor is using We are ready to give you the order for any tool you can suggest and we think it's useful for us ASAP