Create a plugin to increase the number of most used categories

My site is avelim.co.il. The site is on Hebrew wordpress 35, using the theme Weaver 2.2.6 with many customization done by programmers. Currently in wordpress, when you create a new post and you have many categories, the "most used" categories displays the 10 most used categories. I want a plugin created that will change this in two ways: 1. The "most used" categories will display 50 categories. 2. The 50 categories list will be open and will not require scrolling. For this, I need a custom plugin built. The freelancer should send me the plugin as a zip file which I will install on test site. When the plugin is working properly, I will install it on a live site. The work should be done in 24 hours after being awarded the project. Freelancer should allow 7 days for testing after he finishes his work, before getting paid.